QTRX

SEC source: 0000899243-17-028491 · doc4.xml · derivative · entry 9

BAIN CAPITAL VENTURE INVESTORS, LLC · CIK 0001309469 · 10% owner

BAIN CAPITAL VENTURE PARTNERS 2005, L.P. · CIK 0001309470 · 10% owner

BAIN CAPITAL VENTURE FUND 2005, L.P. · CIK 0001309471 · 10% owner

BCIP Associates III, LLC · CIK 0001379475 · 10% owner

BCIP Associates III · CIK 0001379476 · 10% owner

BCIP Associates III-B, LLC · CIK 0001379517 · 10% owner

BCIP Associates III-B · CIK 0001379519 · 10% owner

KRUPKA MICHAEL A · CIK 0001212150 · 10% owner

Agarwal Ajay · CIK 0001708763 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Common Stock · 108,670 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F6 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F7 · derivative.expiration_date: Not applicable.

F2 · ownership.nature: Bain Capital Venture Investors, LLC ("BCVI") is the general partner of Bain Capital Venture Partners 2005, L.P. ("BCVP"), which is the general partner of Bain Capital Venture Fund 2005, L.P. ("Fund 2005"). As a result, BCVP may be deemed to share voting and dispositive power with respect to the securities held by Fund 2005. BCVP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 1,106,387 shares of the Issuer's Series A-1 Preferred Stock, 2,904,268 shares of the Issuer's Series A-2 Preferred Stock, 1,325,258 shares of the Issuer's Series B Preferred Stock, 304,948 shares of the Issuer's Series C Preferred Stock and 353,283 shares of the Issuer's Series D Preferred Stock held by Fund 2005 automatically converted into 344,239, 903,630, 412,339, 94,881 and 109,921 shares of the Issuer's common stock, respectively.

F3 · ownership.nature: Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 157,639 shares of the Issuer's Series A-1 Preferred Stock, 413,802 shares of the Issuer's Series A-2 Preferred Stock, 188,823 shares of the Issuer's Series B Preferred Stock, 43,449 shares of the Issuer's Series C Preferred Stock and 50,336 shares of the Issuer's Series D Preferred Stock held by BCIP Associates III, LLC ("BCIP III"), whose manager is BCIP Associates III ("BCIPA III"), whose managing partner is Boylston Coinvestors, LLC ("Boylston"), automatically converted into 49,047, 128,749, 58,750, 13,518 and 15,663 shares of the Issuer's common stock, respectively. BCIPA III may be deemed to share voting and dispositive power with respect to the securities held by BCIP III. BCIPA III disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F4 · ownership.nature: Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 3,174 shares of the Issuer's Series A-1 Preferred Stock, 8,331 shares of the Issuer's Series A-2 Preferred Stock, 3,799 shares of the Issuer's Series B Preferred Stock, 874 shares of the Issuer's Series C Preferred Stock and 1,013 shares of the Issuer's Series D Preferred Stock held by BCIP Associates III-B, LLC ("BCIP III-B" and together with Fund 2005 and BCIP III, the "Bain Capital Entities"), whose manager is BCIP Associates III-B ("BCIPA III-B"), whose managing partner is Boylston, automatically converted into 987, 2,592, 1,182, 271 and 316 shares of the Issuer's common stock, respectively. BCIPA III-B may be deemed to share voting and dispositive power with respect to the securities held by BCIP III-B. BCIPA III-B disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F5 · ownership.nature: The governance, investment strategy and decision-making process with respect to the investments held by the Bain Capital Entities is directed by the Executive Committee of BCVI, which consists of Michael A. Krupka and Ajay Agarwal. As a result, BCVI and Messrs. Krupka and Agarwal may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Entities. BCVI and Messrs. Krupka and Agarwal disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-17-028491 · doc4.xml · derivative · entry 8

BAIN CAPITAL VENTURE INVESTORS, LLC · CIK 0001309469 · 10% owner

BAIN CAPITAL VENTURE PARTNERS 2005, L.P. · CIK 0001309470 · 10% owner

BAIN CAPITAL VENTURE FUND 2005, L.P. · CIK 0001309471 · 10% owner

BCIP Associates III, LLC · CIK 0001379475 · 10% owner

BCIP Associates III · CIK 0001379476 · 10% owner

BCIP Associates III-B, LLC · CIK 0001379517 · 10% owner

BCIP Associates III-B · CIK 0001379519 · 10% owner

KRUPKA MICHAEL A · CIK 0001212150 · 10% owner

Agarwal Ajay · CIK 0001708763 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Common Stock · 472,271 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F6 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F7 · derivative.expiration_date: Not applicable.

F2 · ownership.nature: Bain Capital Venture Investors, LLC ("BCVI") is the general partner of Bain Capital Venture Partners 2005, L.P. ("BCVP"), which is the general partner of Bain Capital Venture Fund 2005, L.P. ("Fund 2005"). As a result, BCVP may be deemed to share voting and dispositive power with respect to the securities held by Fund 2005. BCVP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 1,106,387 shares of the Issuer's Series A-1 Preferred Stock, 2,904,268 shares of the Issuer's Series A-2 Preferred Stock, 1,325,258 shares of the Issuer's Series B Preferred Stock, 304,948 shares of the Issuer's Series C Preferred Stock and 353,283 shares of the Issuer's Series D Preferred Stock held by Fund 2005 automatically converted into 344,239, 903,630, 412,339, 94,881 and 109,921 shares of the Issuer's common stock, respectively.

F3 · ownership.nature: Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 157,639 shares of the Issuer's Series A-1 Preferred Stock, 413,802 shares of the Issuer's Series A-2 Preferred Stock, 188,823 shares of the Issuer's Series B Preferred Stock, 43,449 shares of the Issuer's Series C Preferred Stock and 50,336 shares of the Issuer's Series D Preferred Stock held by BCIP Associates III, LLC ("BCIP III"), whose manager is BCIP Associates III ("BCIPA III"), whose managing partner is Boylston Coinvestors, LLC ("Boylston"), automatically converted into 49,047, 128,749, 58,750, 13,518 and 15,663 shares of the Issuer's common stock, respectively. BCIPA III may be deemed to share voting and dispositive power with respect to the securities held by BCIP III. BCIPA III disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F4 · ownership.nature: Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 3,174 shares of the Issuer's Series A-1 Preferred Stock, 8,331 shares of the Issuer's Series A-2 Preferred Stock, 3,799 shares of the Issuer's Series B Preferred Stock, 874 shares of the Issuer's Series C Preferred Stock and 1,013 shares of the Issuer's Series D Preferred Stock held by BCIP Associates III-B, LLC ("BCIP III-B" and together with Fund 2005 and BCIP III, the "Bain Capital Entities"), whose manager is BCIP Associates III-B ("BCIPA III-B"), whose managing partner is Boylston, automatically converted into 987, 2,592, 1,182, 271 and 316 shares of the Issuer's common stock, respectively. BCIPA III-B may be deemed to share voting and dispositive power with respect to the securities held by BCIP III-B. BCIPA III-B disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F5 · ownership.nature: The governance, investment strategy and decision-making process with respect to the investments held by the Bain Capital Entities is directed by the Executive Committee of BCVI, which consists of Michael A. Krupka and Ajay Agarwal. As a result, BCVI and Messrs. Krupka and Agarwal may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Entities. BCVI and Messrs. Krupka and Agarwal disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-17-028491 · doc4.xml · derivative · entry 7

BAIN CAPITAL VENTURE INVESTORS, LLC · CIK 0001309469 · 10% owner

BAIN CAPITAL VENTURE PARTNERS 2005, L.P. · CIK 0001309470 · 10% owner

BAIN CAPITAL VENTURE FUND 2005, L.P. · CIK 0001309471 · 10% owner

BCIP Associates III, LLC · CIK 0001379475 · 10% owner

BCIP Associates III · CIK 0001379476 · 10% owner

BCIP Associates III-B, LLC · CIK 0001379517 · 10% owner

BCIP Associates III-B · CIK 0001379519 · 10% owner

KRUPKA MICHAEL A · CIK 0001212150 · 10% owner

Agarwal Ajay · CIK 0001708763 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Common Stock · 1,034,971 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F6 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F7 · derivative.expiration_date: Not applicable.

F2 · ownership.nature: Bain Capital Venture Investors, LLC ("BCVI") is the general partner of Bain Capital Venture Partners 2005, L.P. ("BCVP"), which is the general partner of Bain Capital Venture Fund 2005, L.P. ("Fund 2005"). As a result, BCVP may be deemed to share voting and dispositive power with respect to the securities held by Fund 2005. BCVP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 1,106,387 shares of the Issuer's Series A-1 Preferred Stock, 2,904,268 shares of the Issuer's Series A-2 Preferred Stock, 1,325,258 shares of the Issuer's Series B Preferred Stock, 304,948 shares of the Issuer's Series C Preferred Stock and 353,283 shares of the Issuer's Series D Preferred Stock held by Fund 2005 automatically converted into 344,239, 903,630, 412,339, 94,881 and 109,921 shares of the Issuer's common stock, respectively.

F3 · ownership.nature: Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 157,639 shares of the Issuer's Series A-1 Preferred Stock, 413,802 shares of the Issuer's Series A-2 Preferred Stock, 188,823 shares of the Issuer's Series B Preferred Stock, 43,449 shares of the Issuer's Series C Preferred Stock and 50,336 shares of the Issuer's Series D Preferred Stock held by BCIP Associates III, LLC ("BCIP III"), whose manager is BCIP Associates III ("BCIPA III"), whose managing partner is Boylston Coinvestors, LLC ("Boylston"), automatically converted into 49,047, 128,749, 58,750, 13,518 and 15,663 shares of the Issuer's common stock, respectively. BCIPA III may be deemed to share voting and dispositive power with respect to the securities held by BCIP III. BCIPA III disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F4 · ownership.nature: Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 3,174 shares of the Issuer's Series A-1 Preferred Stock, 8,331 shares of the Issuer's Series A-2 Preferred Stock, 3,799 shares of the Issuer's Series B Preferred Stock, 874 shares of the Issuer's Series C Preferred Stock and 1,013 shares of the Issuer's Series D Preferred Stock held by BCIP Associates III-B, LLC ("BCIP III-B" and together with Fund 2005 and BCIP III, the "Bain Capital Entities"), whose manager is BCIP Associates III-B ("BCIPA III-B"), whose managing partner is Boylston, automatically converted into 987, 2,592, 1,182, 271 and 316 shares of the Issuer's common stock, respectively. BCIPA III-B may be deemed to share voting and dispositive power with respect to the securities held by BCIP III-B. BCIPA III-B disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F5 · ownership.nature: The governance, investment strategy and decision-making process with respect to the investments held by the Bain Capital Entities is directed by the Executive Committee of BCVI, which consists of Michael A. Krupka and Ajay Agarwal. As a result, BCVI and Messrs. Krupka and Agarwal may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Entities. BCVI and Messrs. Krupka and Agarwal disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-17-028491 · doc4.xml · derivative · entry 6

BAIN CAPITAL VENTURE INVESTORS, LLC · CIK 0001309469 · 10% owner

BAIN CAPITAL VENTURE PARTNERS 2005, L.P. · CIK 0001309470 · 10% owner

BAIN CAPITAL VENTURE FUND 2005, L.P. · CIK 0001309471 · 10% owner

BCIP Associates III, LLC · CIK 0001379475 · 10% owner

BCIP Associates III · CIK 0001379476 · 10% owner

BCIP Associates III-B, LLC · CIK 0001379517 · 10% owner

BCIP Associates III-B · CIK 0001379519 · 10% owner

KRUPKA MICHAEL A · CIK 0001212150 · 10% owner

Agarwal Ajay · CIK 0001708763 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Common Stock · 394,273 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F6 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F7 · derivative.expiration_date: Not applicable.

F2 · ownership.nature: Bain Capital Venture Investors, LLC ("BCVI") is the general partner of Bain Capital Venture Partners 2005, L.P. ("BCVP"), which is the general partner of Bain Capital Venture Fund 2005, L.P. ("Fund 2005"). As a result, BCVP may be deemed to share voting and dispositive power with respect to the securities held by Fund 2005. BCVP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 1,106,387 shares of the Issuer's Series A-1 Preferred Stock, 2,904,268 shares of the Issuer's Series A-2 Preferred Stock, 1,325,258 shares of the Issuer's Series B Preferred Stock, 304,948 shares of the Issuer's Series C Preferred Stock and 353,283 shares of the Issuer's Series D Preferred Stock held by Fund 2005 automatically converted into 344,239, 903,630, 412,339, 94,881 and 109,921 shares of the Issuer's common stock, respectively.

F3 · ownership.nature: Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 157,639 shares of the Issuer's Series A-1 Preferred Stock, 413,802 shares of the Issuer's Series A-2 Preferred Stock, 188,823 shares of the Issuer's Series B Preferred Stock, 43,449 shares of the Issuer's Series C Preferred Stock and 50,336 shares of the Issuer's Series D Preferred Stock held by BCIP Associates III, LLC ("BCIP III"), whose manager is BCIP Associates III ("BCIPA III"), whose managing partner is Boylston Coinvestors, LLC ("Boylston"), automatically converted into 49,047, 128,749, 58,750, 13,518 and 15,663 shares of the Issuer's common stock, respectively. BCIPA III may be deemed to share voting and dispositive power with respect to the securities held by BCIP III. BCIPA III disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F4 · ownership.nature: Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 3,174 shares of the Issuer's Series A-1 Preferred Stock, 8,331 shares of the Issuer's Series A-2 Preferred Stock, 3,799 shares of the Issuer's Series B Preferred Stock, 874 shares of the Issuer's Series C Preferred Stock and 1,013 shares of the Issuer's Series D Preferred Stock held by BCIP Associates III-B, LLC ("BCIP III-B" and together with Fund 2005 and BCIP III, the "Bain Capital Entities"), whose manager is BCIP Associates III-B ("BCIPA III-B"), whose managing partner is Boylston, automatically converted into 987, 2,592, 1,182, 271 and 316 shares of the Issuer's common stock, respectively. BCIPA III-B may be deemed to share voting and dispositive power with respect to the securities held by BCIP III-B. BCIPA III-B disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F5 · ownership.nature: The governance, investment strategy and decision-making process with respect to the investments held by the Bain Capital Entities is directed by the Executive Committee of BCVI, which consists of Michael A. Krupka and Ajay Agarwal. As a result, BCVI and Messrs. Krupka and Agarwal may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Entities. BCVI and Messrs. Krupka and Agarwal disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-17-028491 · doc4.xml · nonDerivative · entry 5

BAIN CAPITAL VENTURE INVESTORS, LLC · CIK 0001309469 · 10% owner

BAIN CAPITAL VENTURE PARTNERS 2005, L.P. · CIK 0001309470 · 10% owner

BAIN CAPITAL VENTURE FUND 2005, L.P. · CIK 0001309471 · 10% owner

BCIP Associates III, LLC · CIK 0001379475 · 10% owner

BCIP Associates III · CIK 0001379476 · 10% owner

BCIP Associates III-B, LLC · CIK 0001379517 · 10% owner

BCIP Associates III-B · CIK 0001379519 · 10% owner

KRUPKA MICHAEL A · CIK 0001212150 · 10% owner

Agarwal Ajay · CIK 0001708763 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 2,136,085

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F2 · ownership.nature: Bain Capital Venture Investors, LLC ("BCVI") is the general partner of Bain Capital Venture Partners 2005, L.P. ("BCVP"), which is the general partner of Bain Capital Venture Fund 2005, L.P. ("Fund 2005"). As a result, BCVP may be deemed to share voting and dispositive power with respect to the securities held by Fund 2005. BCVP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 1,106,387 shares of the Issuer's Series A-1 Preferred Stock, 2,904,268 shares of the Issuer's Series A-2 Preferred Stock, 1,325,258 shares of the Issuer's Series B Preferred Stock, 304,948 shares of the Issuer's Series C Preferred Stock and 353,283 shares of the Issuer's Series D Preferred Stock held by Fund 2005 automatically converted into 344,239, 903,630, 412,339, 94,881 and 109,921 shares of the Issuer's common stock, respectively.

F3 · ownership.nature: Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 157,639 shares of the Issuer's Series A-1 Preferred Stock, 413,802 shares of the Issuer's Series A-2 Preferred Stock, 188,823 shares of the Issuer's Series B Preferred Stock, 43,449 shares of the Issuer's Series C Preferred Stock and 50,336 shares of the Issuer's Series D Preferred Stock held by BCIP Associates III, LLC ("BCIP III"), whose manager is BCIP Associates III ("BCIPA III"), whose managing partner is Boylston Coinvestors, LLC ("Boylston"), automatically converted into 49,047, 128,749, 58,750, 13,518 and 15,663 shares of the Issuer's common stock, respectively. BCIPA III may be deemed to share voting and dispositive power with respect to the securities held by BCIP III. BCIPA III disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F4 · ownership.nature: Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 3,174 shares of the Issuer's Series A-1 Preferred Stock, 8,331 shares of the Issuer's Series A-2 Preferred Stock, 3,799 shares of the Issuer's Series B Preferred Stock, 874 shares of the Issuer's Series C Preferred Stock and 1,013 shares of the Issuer's Series D Preferred Stock held by BCIP Associates III-B, LLC ("BCIP III-B" and together with Fund 2005 and BCIP III, the "Bain Capital Entities"), whose manager is BCIP Associates III-B ("BCIPA III-B"), whose managing partner is Boylston, automatically converted into 987, 2,592, 1,182, 271 and 316 shares of the Issuer's common stock, respectively. BCIPA III-B may be deemed to share voting and dispositive power with respect to the securities held by BCIP III-B. BCIPA III-B disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F5 · ownership.nature: The governance, investment strategy and decision-making process with respect to the investments held by the Bain Capital Entities is directed by the Executive Committee of BCVI, which consists of Michael A. Krupka and Ajay Agarwal. As a result, BCVI and Messrs. Krupka and Agarwal may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Entities. BCVI and Messrs. Krupka and Agarwal disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-17-028491 · doc4.xml · nonDerivative · entry 4

BAIN CAPITAL VENTURE INVESTORS, LLC · CIK 0001309469 · 10% owner

BAIN CAPITAL VENTURE PARTNERS 2005, L.P. · CIK 0001309470 · 10% owner

BAIN CAPITAL VENTURE FUND 2005, L.P. · CIK 0001309471 · 10% owner

BCIP Associates III, LLC · CIK 0001379475 · 10% owner

BCIP Associates III · CIK 0001379476 · 10% owner

BCIP Associates III-B, LLC · CIK 0001379517 · 10% owner

BCIP Associates III-B · CIK 0001379519 · 10% owner

KRUPKA MICHAEL A · CIK 0001212150 · 10% owner

Agarwal Ajay · CIK 0001708763 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 2,010,185

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F2 · ownership.nature: Bain Capital Venture Investors, LLC ("BCVI") is the general partner of Bain Capital Venture Partners 2005, L.P. ("BCVP"), which is the general partner of Bain Capital Venture Fund 2005, L.P. ("Fund 2005"). As a result, BCVP may be deemed to share voting and dispositive power with respect to the securities held by Fund 2005. BCVP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 1,106,387 shares of the Issuer's Series A-1 Preferred Stock, 2,904,268 shares of the Issuer's Series A-2 Preferred Stock, 1,325,258 shares of the Issuer's Series B Preferred Stock, 304,948 shares of the Issuer's Series C Preferred Stock and 353,283 shares of the Issuer's Series D Preferred Stock held by Fund 2005 automatically converted into 344,239, 903,630, 412,339, 94,881 and 109,921 shares of the Issuer's common stock, respectively.

F3 · ownership.nature: Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 157,639 shares of the Issuer's Series A-1 Preferred Stock, 413,802 shares of the Issuer's Series A-2 Preferred Stock, 188,823 shares of the Issuer's Series B Preferred Stock, 43,449 shares of the Issuer's Series C Preferred Stock and 50,336 shares of the Issuer's Series D Preferred Stock held by BCIP Associates III, LLC ("BCIP III"), whose manager is BCIP Associates III ("BCIPA III"), whose managing partner is Boylston Coinvestors, LLC ("Boylston"), automatically converted into 49,047, 128,749, 58,750, 13,518 and 15,663 shares of the Issuer's common stock, respectively. BCIPA III may be deemed to share voting and dispositive power with respect to the securities held by BCIP III. BCIPA III disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F4 · ownership.nature: Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 3,174 shares of the Issuer's Series A-1 Preferred Stock, 8,331 shares of the Issuer's Series A-2 Preferred Stock, 3,799 shares of the Issuer's Series B Preferred Stock, 874 shares of the Issuer's Series C Preferred Stock and 1,013 shares of the Issuer's Series D Preferred Stock held by BCIP Associates III-B, LLC ("BCIP III-B" and together with Fund 2005 and BCIP III, the "Bain Capital Entities"), whose manager is BCIP Associates III-B ("BCIPA III-B"), whose managing partner is Boylston, automatically converted into 987, 2,592, 1,182, 271 and 316 shares of the Issuer's common stock, respectively. BCIPA III-B may be deemed to share voting and dispositive power with respect to the securities held by BCIP III-B. BCIPA III-B disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F5 · ownership.nature: The governance, investment strategy and decision-making process with respect to the investments held by the Bain Capital Entities is directed by the Executive Committee of BCVI, which consists of Michael A. Krupka and Ajay Agarwal. As a result, BCVI and Messrs. Krupka and Agarwal may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Entities. BCVI and Messrs. Krupka and Agarwal disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-17-028491 · doc4.xml · nonDerivative · entry 3

BAIN CAPITAL VENTURE INVESTORS, LLC · CIK 0001309469 · 10% owner

BAIN CAPITAL VENTURE PARTNERS 2005, L.P. · CIK 0001309470 · 10% owner

BAIN CAPITAL VENTURE FUND 2005, L.P. · CIK 0001309471 · 10% owner

BCIP Associates III, LLC · CIK 0001379475 · 10% owner

BCIP Associates III · CIK 0001379476 · 10% owner

BCIP Associates III-B, LLC · CIK 0001379517 · 10% owner

BCIP Associates III-B · CIK 0001379519 · 10% owner

KRUPKA MICHAEL A · CIK 0001212150 · 10% owner

Agarwal Ajay · CIK 0001708763 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,901,515

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F2 · ownership.nature: Bain Capital Venture Investors, LLC ("BCVI") is the general partner of Bain Capital Venture Partners 2005, L.P. ("BCVP"), which is the general partner of Bain Capital Venture Fund 2005, L.P. ("Fund 2005"). As a result, BCVP may be deemed to share voting and dispositive power with respect to the securities held by Fund 2005. BCVP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 1,106,387 shares of the Issuer's Series A-1 Preferred Stock, 2,904,268 shares of the Issuer's Series A-2 Preferred Stock, 1,325,258 shares of the Issuer's Series B Preferred Stock, 304,948 shares of the Issuer's Series C Preferred Stock and 353,283 shares of the Issuer's Series D Preferred Stock held by Fund 2005 automatically converted into 344,239, 903,630, 412,339, 94,881 and 109,921 shares of the Issuer's common stock, respectively.

F3 · ownership.nature: Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 157,639 shares of the Issuer's Series A-1 Preferred Stock, 413,802 shares of the Issuer's Series A-2 Preferred Stock, 188,823 shares of the Issuer's Series B Preferred Stock, 43,449 shares of the Issuer's Series C Preferred Stock and 50,336 shares of the Issuer's Series D Preferred Stock held by BCIP Associates III, LLC ("BCIP III"), whose manager is BCIP Associates III ("BCIPA III"), whose managing partner is Boylston Coinvestors, LLC ("Boylston"), automatically converted into 49,047, 128,749, 58,750, 13,518 and 15,663 shares of the Issuer's common stock, respectively. BCIPA III may be deemed to share voting and dispositive power with respect to the securities held by BCIP III. BCIPA III disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F4 · ownership.nature: Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 3,174 shares of the Issuer's Series A-1 Preferred Stock, 8,331 shares of the Issuer's Series A-2 Preferred Stock, 3,799 shares of the Issuer's Series B Preferred Stock, 874 shares of the Issuer's Series C Preferred Stock and 1,013 shares of the Issuer's Series D Preferred Stock held by BCIP Associates III-B, LLC ("BCIP III-B" and together with Fund 2005 and BCIP III, the "Bain Capital Entities"), whose manager is BCIP Associates III-B ("BCIPA III-B"), whose managing partner is Boylston, automatically converted into 987, 2,592, 1,182, 271 and 316 shares of the Issuer's common stock, respectively. BCIPA III-B may be deemed to share voting and dispositive power with respect to the securities held by BCIP III-B. BCIPA III-B disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F5 · ownership.nature: The governance, investment strategy and decision-making process with respect to the investments held by the Bain Capital Entities is directed by the Executive Committee of BCVI, which consists of Michael A. Krupka and Ajay Agarwal. As a result, BCVI and Messrs. Krupka and Agarwal may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Entities. BCVI and Messrs. Krupka and Agarwal disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-17-028491 · doc4.xml · nonDerivative · entry 2

BAIN CAPITAL VENTURE INVESTORS, LLC · CIK 0001309469 · 10% owner

BAIN CAPITAL VENTURE PARTNERS 2005, L.P. · CIK 0001309470 · 10% owner

BAIN CAPITAL VENTURE FUND 2005, L.P. · CIK 0001309471 · 10% owner

BCIP Associates III, LLC · CIK 0001379475 · 10% owner

BCIP Associates III · CIK 0001379476 · 10% owner

BCIP Associates III-B, LLC · CIK 0001379517 · 10% owner

BCIP Associates III-B · CIK 0001379519 · 10% owner

KRUPKA MICHAEL A · CIK 0001212150 · 10% owner

Agarwal Ajay · CIK 0001708763 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,429,244

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F2 · ownership.nature: Bain Capital Venture Investors, LLC ("BCVI") is the general partner of Bain Capital Venture Partners 2005, L.P. ("BCVP"), which is the general partner of Bain Capital Venture Fund 2005, L.P. ("Fund 2005"). As a result, BCVP may be deemed to share voting and dispositive power with respect to the securities held by Fund 2005. BCVP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 1,106,387 shares of the Issuer's Series A-1 Preferred Stock, 2,904,268 shares of the Issuer's Series A-2 Preferred Stock, 1,325,258 shares of the Issuer's Series B Preferred Stock, 304,948 shares of the Issuer's Series C Preferred Stock and 353,283 shares of the Issuer's Series D Preferred Stock held by Fund 2005 automatically converted into 344,239, 903,630, 412,339, 94,881 and 109,921 shares of the Issuer's common stock, respectively.

F3 · ownership.nature: Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 157,639 shares of the Issuer's Series A-1 Preferred Stock, 413,802 shares of the Issuer's Series A-2 Preferred Stock, 188,823 shares of the Issuer's Series B Preferred Stock, 43,449 shares of the Issuer's Series C Preferred Stock and 50,336 shares of the Issuer's Series D Preferred Stock held by BCIP Associates III, LLC ("BCIP III"), whose manager is BCIP Associates III ("BCIPA III"), whose managing partner is Boylston Coinvestors, LLC ("Boylston"), automatically converted into 49,047, 128,749, 58,750, 13,518 and 15,663 shares of the Issuer's common stock, respectively. BCIPA III may be deemed to share voting and dispositive power with respect to the securities held by BCIP III. BCIPA III disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F4 · ownership.nature: Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 3,174 shares of the Issuer's Series A-1 Preferred Stock, 8,331 shares of the Issuer's Series A-2 Preferred Stock, 3,799 shares of the Issuer's Series B Preferred Stock, 874 shares of the Issuer's Series C Preferred Stock and 1,013 shares of the Issuer's Series D Preferred Stock held by BCIP Associates III-B, LLC ("BCIP III-B" and together with Fund 2005 and BCIP III, the "Bain Capital Entities"), whose manager is BCIP Associates III-B ("BCIPA III-B"), whose managing partner is Boylston, automatically converted into 987, 2,592, 1,182, 271 and 316 shares of the Issuer's common stock, respectively. BCIPA III-B may be deemed to share voting and dispositive power with respect to the securities held by BCIP III-B. BCIPA III-B disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F5 · ownership.nature: The governance, investment strategy and decision-making process with respect to the investments held by the Bain Capital Entities is directed by the Executive Committee of BCVI, which consists of Michael A. Krupka and Ajay Agarwal. As a result, BCVI and Messrs. Krupka and Agarwal may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Entities. BCVI and Messrs. Krupka and Agarwal disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-17-028491 · doc4.xml · nonDerivative · entry 1

BAIN CAPITAL VENTURE INVESTORS, LLC · CIK 0001309469 · 10% owner

BAIN CAPITAL VENTURE PARTNERS 2005, L.P. · CIK 0001309470 · 10% owner

BAIN CAPITAL VENTURE FUND 2005, L.P. · CIK 0001309471 · 10% owner

BCIP Associates III, LLC · CIK 0001379475 · 10% owner

BCIP Associates III · CIK 0001379476 · 10% owner

BCIP Associates III-B, LLC · CIK 0001379517 · 10% owner

BCIP Associates III-B · CIK 0001379519 · 10% owner

KRUPKA MICHAEL A · CIK 0001212150 · 10% owner

Agarwal Ajay · CIK 0001708763 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 394,273

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F2 · ownership.nature: Bain Capital Venture Investors, LLC ("BCVI") is the general partner of Bain Capital Venture Partners 2005, L.P. ("BCVP"), which is the general partner of Bain Capital Venture Fund 2005, L.P. ("Fund 2005"). As a result, BCVP may be deemed to share voting and dispositive power with respect to the securities held by Fund 2005. BCVP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 1,106,387 shares of the Issuer's Series A-1 Preferred Stock, 2,904,268 shares of the Issuer's Series A-2 Preferred Stock, 1,325,258 shares of the Issuer's Series B Preferred Stock, 304,948 shares of the Issuer's Series C Preferred Stock and 353,283 shares of the Issuer's Series D Preferred Stock held by Fund 2005 automatically converted into 344,239, 903,630, 412,339, 94,881 and 109,921 shares of the Issuer's common stock, respectively.

F3 · ownership.nature: Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 157,639 shares of the Issuer's Series A-1 Preferred Stock, 413,802 shares of the Issuer's Series A-2 Preferred Stock, 188,823 shares of the Issuer's Series B Preferred Stock, 43,449 shares of the Issuer's Series C Preferred Stock and 50,336 shares of the Issuer's Series D Preferred Stock held by BCIP Associates III, LLC ("BCIP III"), whose manager is BCIP Associates III ("BCIPA III"), whose managing partner is Boylston Coinvestors, LLC ("Boylston"), automatically converted into 49,047, 128,749, 58,750, 13,518 and 15,663 shares of the Issuer's common stock, respectively. BCIPA III may be deemed to share voting and dispositive power with respect to the securities held by BCIP III. BCIPA III disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F4 · ownership.nature: Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 3,174 shares of the Issuer's Series A-1 Preferred Stock, 8,331 shares of the Issuer's Series A-2 Preferred Stock, 3,799 shares of the Issuer's Series B Preferred Stock, 874 shares of the Issuer's Series C Preferred Stock and 1,013 shares of the Issuer's Series D Preferred Stock held by BCIP Associates III-B, LLC ("BCIP III-B" and together with Fund 2005 and BCIP III, the "Bain Capital Entities"), whose manager is BCIP Associates III-B ("BCIPA III-B"), whose managing partner is Boylston, automatically converted into 987, 2,592, 1,182, 271 and 316 shares of the Issuer's common stock, respectively. BCIPA III-B may be deemed to share voting and dispositive power with respect to the securities held by BCIP III-B. BCIPA III-B disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F5 · ownership.nature: The governance, investment strategy and decision-making process with respect to the investments held by the Bain Capital Entities is directed by the Executive Committee of BCVI, which consists of Michael A. Krupka and Ajay Agarwal. As a result, BCVI and Messrs. Krupka and Agarwal may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Entities. BCVI and Messrs. Krupka and Agarwal disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0001104659-17-073158 · a4.xml · derivative · entry 8

Flagship Ventures Fund 2004 L P · CIK 0001299790 · 10% owner

Flagship Ventures General Partner LLC · CIK 0001400249 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 109,770 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F3 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F4 · derivative.expiration_date: Not applicable.

F2 · ownership.direct: Held by Flagship Ventures Fund 2004, L.P. Flagship Ventures General Partner LLC (the "GP") is the General Partner of Flagship Ventures Fund 2004, L.P. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the Managers of the GP. The GP, Dr. Afeyan and Mr. Kania may be deemed to possess voting and investment control over all shares held by Flagship Ventures Fund 2004, L.P. Each of the reporting persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-17-073158 · a4.xml · derivative · entry 7

Flagship Ventures Fund 2004 L P · CIK 0001299790 · 10% owner

Flagship Ventures General Partner LLC · CIK 0001400249 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 477,042 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F3 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F4 · derivative.expiration_date: Not applicable.

F2 · ownership.direct: Held by Flagship Ventures Fund 2004, L.P. Flagship Ventures General Partner LLC (the "GP") is the General Partner of Flagship Ventures Fund 2004, L.P. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the Managers of the GP. The GP, Dr. Afeyan and Mr. Kania may be deemed to possess voting and investment control over all shares held by Flagship Ventures Fund 2004, L.P. Each of the reporting persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-17-073158 · a4.xml · derivative · entry 6

Flagship Ventures Fund 2004 L P · CIK 0001299790 · 10% owner

Flagship Ventures General Partner LLC · CIK 0001400249 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 1,045,426 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F3 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F4 · derivative.expiration_date: Not applicable.

F2 · ownership.direct: Held by Flagship Ventures Fund 2004, L.P. Flagship Ventures General Partner LLC (the "GP") is the General Partner of Flagship Ventures Fund 2004, L.P. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the Managers of the GP. The GP, Dr. Afeyan and Mr. Kania may be deemed to possess voting and investment control over all shares held by Flagship Ventures Fund 2004, L.P. Each of the reporting persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-17-073158 · a4.xml · derivative · entry 5

Flagship Ventures Fund 2004 L P · CIK 0001299790 · 10% owner

Flagship Ventures General Partner LLC · CIK 0001400249 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 398,257 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F3 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F4 · derivative.expiration_date: Not applicable.

F2 · ownership.direct: Held by Flagship Ventures Fund 2004, L.P. Flagship Ventures General Partner LLC (the "GP") is the General Partner of Flagship Ventures Fund 2004, L.P. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the Managers of the GP. The GP, Dr. Afeyan and Mr. Kania may be deemed to possess voting and investment control over all shares held by Flagship Ventures Fund 2004, L.P. Each of the reporting persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-17-073158 · a4.xml · nonDerivative · entry 4

Flagship Ventures Fund 2004 L P · CIK 0001299790 · 10% owner

Flagship Ventures General Partner LLC · CIK 0001400249 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,030,495

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F2 · ownership.direct: Held by Flagship Ventures Fund 2004, L.P. Flagship Ventures General Partner LLC (the "GP") is the General Partner of Flagship Ventures Fund 2004, L.P. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the Managers of the GP. The GP, Dr. Afeyan and Mr. Kania may be deemed to possess voting and investment control over all shares held by Flagship Ventures Fund 2004, L.P. Each of the reporting persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-17-073158 · a4.xml · nonDerivative · entry 3

Flagship Ventures Fund 2004 L P · CIK 0001299790 · 10% owner

Flagship Ventures General Partner LLC · CIK 0001400249 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,920,725

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F2 · ownership.direct: Held by Flagship Ventures Fund 2004, L.P. Flagship Ventures General Partner LLC (the "GP") is the General Partner of Flagship Ventures Fund 2004, L.P. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the Managers of the GP. The GP, Dr. Afeyan and Mr. Kania may be deemed to possess voting and investment control over all shares held by Flagship Ventures Fund 2004, L.P. Each of the reporting persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-17-073158 · a4.xml · nonDerivative · entry 2

Flagship Ventures Fund 2004 L P · CIK 0001299790 · 10% owner

Flagship Ventures General Partner LLC · CIK 0001400249 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,443,683

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F2 · ownership.direct: Held by Flagship Ventures Fund 2004, L.P. Flagship Ventures General Partner LLC (the "GP") is the General Partner of Flagship Ventures Fund 2004, L.P. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the Managers of the GP. The GP, Dr. Afeyan and Mr. Kania may be deemed to possess voting and investment control over all shares held by Flagship Ventures Fund 2004, L.P. Each of the reporting persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-17-073158 · a4.xml · nonDerivative · entry 1

Flagship Ventures Fund 2004 L P · CIK 0001299790 · 10% owner

Flagship Ventures General Partner LLC · CIK 0001400249 · 10% owner

AFEYAN NOUBAR · CIK 0001222012 · 10% owner

KANIA EDWIN M JR · CIK 0001255927 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 398,257

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F2 · ownership.direct: Held by Flagship Ventures Fund 2004, L.P. Flagship Ventures General Partner LLC (the "GP") is the General Partner of Flagship Ventures Fund 2004, L.P. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the Managers of the GP. The GP, Dr. Afeyan and Mr. Kania may be deemed to possess voting and investment control over all shares held by Flagship Ventures Fund 2004, L.P. Each of the reporting persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

SEC source: 0001104659-17-073156 · a4.xml · derivative · entry 13

ARCH VENTURE FUND VI LP · CIK 0001222135 · 10% owner

ARCH Venture Fund VIII Overage, L.P. · CIK 0001617237 · 10% owner

ARCH VENTURE PARTNERS VI LP · CIK 0001274410 · 10% owner

ARCH VENTURE PARTNERS VI LLC · CIK 0001274412 · 10% owner

ARCH Venture Partners VIII, LLC · CIK 0001616165 · 10% owner

BYBEE CLINTON · CIK 0001219043 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 1,271,684 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F5 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F6 · derivative.expiration_date: Not applicable.

F3 · ownership.direct: The shares are held of record by ARCH Venture Fund VIII Overage, L.P. ("ARCH Fund Overage"). The sole general partner of ARCH Fund Overage is ARCH Venture Partners VIII, LLC ("ARCH VIII LLC"), which may be deemed to beneficially own the shares held by ARCH Fund Overage. ARCH VIII LLC disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein. As a managing director of ARCH VIII LLC, the Reporting Person may be deemed to beneficially own the shares held by ARCH Fund Overage. The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-17-073156 · a4.xml · derivative · entry 12

ARCH VENTURE FUND VI LP · CIK 0001222135 · 10% owner

ARCH Venture Fund VIII Overage, L.P. · CIK 0001617237 · 10% owner

ARCH VENTURE PARTNERS VI LP · CIK 0001274410 · 10% owner

ARCH VENTURE PARTNERS VI LLC · CIK 0001274412 · 10% owner

ARCH Venture Partners VIII, LLC · CIK 0001616165 · 10% owner

BYBEE CLINTON · CIK 0001219043 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 381,507 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F5 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F6 · derivative.expiration_date: Not applicable.

F2 · ownership.direct: The shares are held of record by ARCH Venture Fund VI, L.P. ("ARCH Fund VI"). The sole general partner of ARCH Fund VI is ARCH Venture Partners VI, L.P. ("ARCH Partners VI"), which may be deemed to beneficially own the shares held by ARCH Fund VI. The sole general partner of ARCH Partners VI is ARCH Venture Partners VI, LLC ("ARCH VI LLC"), which may be deemed to beneficially own the shares held by ARCH Fund VI. ARCH Partners VI and ARCH VI LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. As a managing director of ARCH VI LLC, the Reporting Person may be deemed to beneficially own the shares held by ARCH Fund VI. The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-17-073156 · a4.xml · derivative · entry 11

ARCH VENTURE FUND VI LP · CIK 0001222135 · 10% owner

ARCH Venture Fund VIII Overage, L.P. · CIK 0001617237 · 10% owner

ARCH VENTURE PARTNERS VI LP · CIK 0001274410 · 10% owner

ARCH VENTURE PARTNERS VI LLC · CIK 0001274412 · 10% owner

ARCH Venture Partners VIII, LLC · CIK 0001616165 · 10% owner

BYBEE CLINTON · CIK 0001219043 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 109,769 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F5 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F6 · derivative.expiration_date: Not applicable.

F2 · ownership.direct: The shares are held of record by ARCH Venture Fund VI, L.P. ("ARCH Fund VI"). The sole general partner of ARCH Fund VI is ARCH Venture Partners VI, L.P. ("ARCH Partners VI"), which may be deemed to beneficially own the shares held by ARCH Fund VI. The sole general partner of ARCH Partners VI is ARCH Venture Partners VI, LLC ("ARCH VI LLC"), which may be deemed to beneficially own the shares held by ARCH Fund VI. ARCH Partners VI and ARCH VI LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. As a managing director of ARCH VI LLC, the Reporting Person may be deemed to beneficially own the shares held by ARCH Fund VI. The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-17-073156 · a4.xml · derivative · entry 10

ARCH VENTURE FUND VI LP · CIK 0001222135 · 10% owner

ARCH Venture Fund VIII Overage, L.P. · CIK 0001617237 · 10% owner

ARCH VENTURE PARTNERS VI LP · CIK 0001274410 · 10% owner

ARCH VENTURE PARTNERS VI LLC · CIK 0001274412 · 10% owner

ARCH Venture Partners VIII, LLC · CIK 0001616165 · 10% owner

BYBEE CLINTON · CIK 0001219043 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 477,042 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F5 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F6 · derivative.expiration_date: Not applicable.

F2 · ownership.direct: The shares are held of record by ARCH Venture Fund VI, L.P. ("ARCH Fund VI"). The sole general partner of ARCH Fund VI is ARCH Venture Partners VI, L.P. ("ARCH Partners VI"), which may be deemed to beneficially own the shares held by ARCH Fund VI. The sole general partner of ARCH Partners VI is ARCH Venture Partners VI, LLC ("ARCH VI LLC"), which may be deemed to beneficially own the shares held by ARCH Fund VI. ARCH Partners VI and ARCH VI LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. As a managing director of ARCH VI LLC, the Reporting Person may be deemed to beneficially own the shares held by ARCH Fund VI. The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-17-073156 · a4.xml · derivative · entry 9

ARCH VENTURE FUND VI LP · CIK 0001222135 · 10% owner

ARCH Venture Fund VIII Overage, L.P. · CIK 0001617237 · 10% owner

ARCH VENTURE PARTNERS VI LP · CIK 0001274410 · 10% owner

ARCH VENTURE PARTNERS VI LLC · CIK 0001274412 · 10% owner

ARCH Venture Partners VIII, LLC · CIK 0001616165 · 10% owner

BYBEE CLINTON · CIK 0001219043 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 1,045,426 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F5 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F6 · derivative.expiration_date: Not applicable.

F2 · ownership.direct: The shares are held of record by ARCH Venture Fund VI, L.P. ("ARCH Fund VI"). The sole general partner of ARCH Fund VI is ARCH Venture Partners VI, L.P. ("ARCH Partners VI"), which may be deemed to beneficially own the shares held by ARCH Fund VI. The sole general partner of ARCH Partners VI is ARCH Venture Partners VI, LLC ("ARCH VI LLC"), which may be deemed to beneficially own the shares held by ARCH Fund VI. ARCH Partners VI and ARCH VI LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. As a managing director of ARCH VI LLC, the Reporting Person may be deemed to beneficially own the shares held by ARCH Fund VI. The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-17-073156 · a4.xml · derivative · entry 8

ARCH VENTURE FUND VI LP · CIK 0001222135 · 10% owner

ARCH Venture Fund VIII Overage, L.P. · CIK 0001617237 · 10% owner

ARCH VENTURE PARTNERS VI LP · CIK 0001274410 · 10% owner

ARCH VENTURE PARTNERS VI LLC · CIK 0001274412 · 10% owner

ARCH Venture Partners VIII, LLC · CIK 0001616165 · 10% owner

BYBEE CLINTON · CIK 0001219043 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 398,257 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F5 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F6 · derivative.expiration_date: Not applicable.

F2 · ownership.direct: The shares are held of record by ARCH Venture Fund VI, L.P. ("ARCH Fund VI"). The sole general partner of ARCH Fund VI is ARCH Venture Partners VI, L.P. ("ARCH Partners VI"), which may be deemed to beneficially own the shares held by ARCH Fund VI. The sole general partner of ARCH Partners VI is ARCH Venture Partners VI, LLC ("ARCH VI LLC"), which may be deemed to beneficially own the shares held by ARCH Fund VI. ARCH Partners VI and ARCH VI LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. As a managing director of ARCH VI LLC, the Reporting Person may be deemed to beneficially own the shares held by ARCH Fund VI. The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-17-073156 · a4.xml · nonDerivative · entry 7

ARCH VENTURE FUND VI LP · CIK 0001222135 · 10% owner

ARCH Venture Fund VIII Overage, L.P. · CIK 0001617237 · 10% owner

ARCH VENTURE PARTNERS VI LP · CIK 0001274410 · 10% owner

ARCH VENTURE PARTNERS VI LLC · CIK 0001274412 · 10% owner

ARCH Venture Partners VIII, LLC · CIK 0001616165 · 10% owner

BYBEE CLINTON · CIK 0001219043 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,537,684

F4 · shares: Reflects shares purchased in the Issuer's initial public offering.

F3 · ownership.direct: The shares are held of record by ARCH Venture Fund VIII Overage, L.P. ("ARCH Fund Overage"). The sole general partner of ARCH Fund Overage is ARCH Venture Partners VIII, LLC ("ARCH VIII LLC"), which may be deemed to beneficially own the shares held by ARCH Fund Overage. ARCH VIII LLC disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein. As a managing director of ARCH VIII LLC, the Reporting Person may be deemed to beneficially own the shares held by ARCH Fund Overage. The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-17-073156 · a4.xml · nonDerivative · entry 6

ARCH VENTURE FUND VI LP · CIK 0001222135 · 10% owner

ARCH Venture Fund VIII Overage, L.P. · CIK 0001617237 · 10% owner

ARCH VENTURE PARTNERS VI LP · CIK 0001274410 · 10% owner

ARCH VENTURE PARTNERS VI LLC · CIK 0001274412 · 10% owner

ARCH Venture Partners VIII, LLC · CIK 0001616165 · 10% owner

BYBEE CLINTON · CIK 0001219043 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,271,684

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F3 · ownership.direct: The shares are held of record by ARCH Venture Fund VIII Overage, L.P. ("ARCH Fund Overage"). The sole general partner of ARCH Fund Overage is ARCH Venture Partners VIII, LLC ("ARCH VIII LLC"), which may be deemed to beneficially own the shares held by ARCH Fund Overage. ARCH VIII LLC disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein. As a managing director of ARCH VIII LLC, the Reporting Person may be deemed to beneficially own the shares held by ARCH Fund Overage. The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-17-073156 · a4.xml · nonDerivative · entry 5

ARCH VENTURE FUND VI LP · CIK 0001222135 · 10% owner

ARCH Venture Fund VIII Overage, L.P. · CIK 0001617237 · 10% owner

ARCH VENTURE PARTNERS VI LP · CIK 0001274410 · 10% owner

ARCH VENTURE PARTNERS VI LLC · CIK 0001274412 · 10% owner

ARCH Venture Partners VIII, LLC · CIK 0001616165 · 10% owner

BYBEE CLINTON · CIK 0001219043 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,412,001

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F2 · ownership.direct: The shares are held of record by ARCH Venture Fund VI, L.P. ("ARCH Fund VI"). The sole general partner of ARCH Fund VI is ARCH Venture Partners VI, L.P. ("ARCH Partners VI"), which may be deemed to beneficially own the shares held by ARCH Fund VI. The sole general partner of ARCH Partners VI is ARCH Venture Partners VI, LLC ("ARCH VI LLC"), which may be deemed to beneficially own the shares held by ARCH Fund VI. ARCH Partners VI and ARCH VI LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. As a managing director of ARCH VI LLC, the Reporting Person may be deemed to beneficially own the shares held by ARCH Fund VI. The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-17-073156 · a4.xml · nonDerivative · entry 4

ARCH VENTURE FUND VI LP · CIK 0001222135 · 10% owner

ARCH Venture Fund VIII Overage, L.P. · CIK 0001617237 · 10% owner

ARCH VENTURE PARTNERS VI LP · CIK 0001274410 · 10% owner

ARCH VENTURE PARTNERS VI LLC · CIK 0001274412 · 10% owner

ARCH Venture Partners VIII, LLC · CIK 0001616165 · 10% owner

BYBEE CLINTON · CIK 0001219043 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,030,494

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F2 · ownership.direct: The shares are held of record by ARCH Venture Fund VI, L.P. ("ARCH Fund VI"). The sole general partner of ARCH Fund VI is ARCH Venture Partners VI, L.P. ("ARCH Partners VI"), which may be deemed to beneficially own the shares held by ARCH Fund VI. The sole general partner of ARCH Partners VI is ARCH Venture Partners VI, LLC ("ARCH VI LLC"), which may be deemed to beneficially own the shares held by ARCH Fund VI. ARCH Partners VI and ARCH VI LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. As a managing director of ARCH VI LLC, the Reporting Person may be deemed to beneficially own the shares held by ARCH Fund VI. The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-17-073156 · a4.xml · nonDerivative · entry 3

ARCH VENTURE FUND VI LP · CIK 0001222135 · 10% owner

ARCH Venture Fund VIII Overage, L.P. · CIK 0001617237 · 10% owner

ARCH VENTURE PARTNERS VI LP · CIK 0001274410 · 10% owner

ARCH VENTURE PARTNERS VI LLC · CIK 0001274412 · 10% owner

ARCH Venture Partners VIII, LLC · CIK 0001616165 · 10% owner

BYBEE CLINTON · CIK 0001219043 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,920,725

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F2 · ownership.direct: The shares are held of record by ARCH Venture Fund VI, L.P. ("ARCH Fund VI"). The sole general partner of ARCH Fund VI is ARCH Venture Partners VI, L.P. ("ARCH Partners VI"), which may be deemed to beneficially own the shares held by ARCH Fund VI. The sole general partner of ARCH Partners VI is ARCH Venture Partners VI, LLC ("ARCH VI LLC"), which may be deemed to beneficially own the shares held by ARCH Fund VI. ARCH Partners VI and ARCH VI LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. As a managing director of ARCH VI LLC, the Reporting Person may be deemed to beneficially own the shares held by ARCH Fund VI. The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-17-073156 · a4.xml · nonDerivative · entry 2

ARCH VENTURE FUND VI LP · CIK 0001222135 · 10% owner

ARCH Venture Fund VIII Overage, L.P. · CIK 0001617237 · 10% owner

ARCH VENTURE PARTNERS VI LP · CIK 0001274410 · 10% owner

ARCH VENTURE PARTNERS VI LLC · CIK 0001274412 · 10% owner

ARCH Venture Partners VIII, LLC · CIK 0001616165 · 10% owner

BYBEE CLINTON · CIK 0001219043 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,443,683

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F2 · ownership.direct: The shares are held of record by ARCH Venture Fund VI, L.P. ("ARCH Fund VI"). The sole general partner of ARCH Fund VI is ARCH Venture Partners VI, L.P. ("ARCH Partners VI"), which may be deemed to beneficially own the shares held by ARCH Fund VI. The sole general partner of ARCH Partners VI is ARCH Venture Partners VI, LLC ("ARCH VI LLC"), which may be deemed to beneficially own the shares held by ARCH Fund VI. ARCH Partners VI and ARCH VI LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. As a managing director of ARCH VI LLC, the Reporting Person may be deemed to beneficially own the shares held by ARCH Fund VI. The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-17-073156 · a4.xml · nonDerivative · entry 1

ARCH VENTURE FUND VI LP · CIK 0001222135 · 10% owner

ARCH Venture Fund VIII Overage, L.P. · CIK 0001617237 · 10% owner

ARCH VENTURE PARTNERS VI LP · CIK 0001274410 · 10% owner

ARCH VENTURE PARTNERS VI LLC · CIK 0001274412 · 10% owner

ARCH Venture Partners VIII, LLC · CIK 0001616165 · 10% owner

BYBEE CLINTON · CIK 0001219043 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 398,257

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F2 · ownership.direct: The shares are held of record by ARCH Venture Fund VI, L.P. ("ARCH Fund VI"). The sole general partner of ARCH Fund VI is ARCH Venture Partners VI, L.P. ("ARCH Partners VI"), which may be deemed to beneficially own the shares held by ARCH Fund VI. The sole general partner of ARCH Partners VI is ARCH Venture Partners VI, LLC ("ARCH VI LLC"), which may be deemed to beneficially own the shares held by ARCH Fund VI. ARCH Partners VI and ARCH VI LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. As a managing director of ARCH VI LLC, the Reporting Person may be deemed to beneficially own the shares held by ARCH Fund VI. The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-17-073153 · a4.xml · derivative · entry 17

WALT DAVID R · CIK 0001205236 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 135,647 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F3 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F4 · derivative.expiration_date: Not applicable.

SEC source: 0001104659-17-073153 · a4.xml · derivative · entry 16

WALT DAVID R · CIK 0001205236 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 28,691 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F3 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F4 · derivative.expiration_date: Not applicable.

SEC source: 0001104659-17-073153 · a4.xml · derivative · entry 9

WALT DAVID R · CIK 0001205236 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 334,985 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F3 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F4 · derivative.expiration_date: Not applicable.

SEC source: 0001104659-17-073153 · a4.xml · derivative · entry 8

WALT DAVID R · CIK 0001205236 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 86,517 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F3 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F4 · derivative.expiration_date: Not applicable.

SEC source: 0001104659-17-073153 · a4.xml · derivative · entry 7

WALT DAVID R · CIK 0001205236 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 32,959 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F3 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F4 · derivative.expiration_date: Not applicable.

SEC source: 0001104659-17-073153 · a4.xml · nonDerivative · entry 6

WALT DAVID R · CIK 0001205236 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,215,500

F2 · shares: Reflects shares purchased in the Issuer's initial public offering.

SEC source: 0001104659-17-073153 · a4.xml · nonDerivative · entry 5

WALT DAVID R · CIK 0001205236 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,015,500

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

SEC source: 0001104659-17-073153 · a4.xml · nonDerivative · entry 4

WALT DAVID R · CIK 0001205236 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 879,853

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

SEC source: 0001104659-17-073153 · a4.xml · nonDerivative · entry 3

WALT DAVID R · CIK 0001205236 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 851,162

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

SEC source: 0001104659-17-073153 · a4.xml · nonDerivative · entry 2

WALT DAVID R · CIK 0001205236 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 516,177

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

SEC source: 0001104659-17-073153 · a4.xml · nonDerivative · entry 1

WALT DAVID R · CIK 0001205236 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 429,660

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

SEC source: 0001104659-17-073152 · a4.xml · derivative · entry 2

DEKKERS MARIJN E · CIK 0001216068 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 77,378 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F2 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F3 · derivative.expiration_date: Not applicable.

SEC source: 0001104659-17-073152 · a4.xml · nonDerivative · entry 1

DEKKERS MARIJN E · CIK 0001216068 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 77,378

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

SEC source: 0001104659-17-073155 · a4.xml · derivative · entry 22

CRANDELL KEITH · CIK 0001219039 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · Held by ARCH Venture Fund VIII Overage, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 1,271,684 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F5 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F6 · derivative.expiration_date: Not applicable.

F3 · ownership.nature: The shares are held of record by ARCH Venture Fund VIII Overage, L.P. ("ARCH Fund Overage"). The sole general partner of ARCH Fund Overage is ARCH Venture Partners VIII, LLC ("ARCH VIII LLC"), which may be deemed to beneficially own the shares held by ARCH Fund Overage. ARCH VIII LLC disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein. As a managing director of ARCH VIII LLC, the Reporting Person may be deemed to beneficially own the shares held by ARCH Fund Overage. The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-17-073155 · a4.xml · derivative · entry 21

CRANDELL KEITH · CIK 0001219039 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · Held by ARCH Venture Fund VI, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 381,507 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F5 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F6 · derivative.expiration_date: Not applicable.

F2 · ownership.nature: The shares are held of record by ARCH Venture Fund VI, L.P. ("ARCH Fund VI"). The sole general partner of ARCH Fund VI is ARCH Venture Partners VI, L.P. ("ARCH Partners VI"), which may be deemed to beneficially own the shares held by ARCH Fund VI. The sole general partner of ARCH Partners VI is ARCH Venture Partners VI, LLC ("ARCH VI LLC"), which may be deemed to beneficially own the shares held by ARCH Fund VI. ARCH Partners VI and ARCH VI LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. As a managing director of ARCH VI LLC, the Reporting Person may be deemed to beneficially own the shares held by ARCH Fund VI. The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-17-073155 · a4.xml · derivative · entry 20

CRANDELL KEITH · CIK 0001219039 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · Held by ARCH Venture Fund VI, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 109,769 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F5 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F6 · derivative.expiration_date: Not applicable.

F2 · ownership.nature: The shares are held of record by ARCH Venture Fund VI, L.P. ("ARCH Fund VI"). The sole general partner of ARCH Fund VI is ARCH Venture Partners VI, L.P. ("ARCH Partners VI"), which may be deemed to beneficially own the shares held by ARCH Fund VI. The sole general partner of ARCH Partners VI is ARCH Venture Partners VI, LLC ("ARCH VI LLC"), which may be deemed to beneficially own the shares held by ARCH Fund VI. ARCH Partners VI and ARCH VI LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. As a managing director of ARCH VI LLC, the Reporting Person may be deemed to beneficially own the shares held by ARCH Fund VI. The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-17-073155 · a4.xml · derivative · entry 10

CRANDELL KEITH · CIK 0001219039 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · Held by ARCH Venture Fund VI, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 477,042 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F5 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F6 · derivative.expiration_date: Not applicable.

F2 · ownership.nature: The shares are held of record by ARCH Venture Fund VI, L.P. ("ARCH Fund VI"). The sole general partner of ARCH Fund VI is ARCH Venture Partners VI, L.P. ("ARCH Partners VI"), which may be deemed to beneficially own the shares held by ARCH Fund VI. The sole general partner of ARCH Partners VI is ARCH Venture Partners VI, LLC ("ARCH VI LLC"), which may be deemed to beneficially own the shares held by ARCH Fund VI. ARCH Partners VI and ARCH VI LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. As a managing director of ARCH VI LLC, the Reporting Person may be deemed to beneficially own the shares held by ARCH Fund VI. The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-17-073155 · a4.xml · derivative · entry 9

CRANDELL KEITH · CIK 0001219039 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · Held by ARCH Venture Fund VI, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 1,045,426 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F5 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F6 · derivative.expiration_date: Not applicable.

F2 · ownership.nature: The shares are held of record by ARCH Venture Fund VI, L.P. ("ARCH Fund VI"). The sole general partner of ARCH Fund VI is ARCH Venture Partners VI, L.P. ("ARCH Partners VI"), which may be deemed to beneficially own the shares held by ARCH Fund VI. The sole general partner of ARCH Partners VI is ARCH Venture Partners VI, LLC ("ARCH VI LLC"), which may be deemed to beneficially own the shares held by ARCH Fund VI. ARCH Partners VI and ARCH VI LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. As a managing director of ARCH VI LLC, the Reporting Person may be deemed to beneficially own the shares held by ARCH Fund VI. The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-17-073155 · a4.xml · derivative · entry 8

CRANDELL KEITH · CIK 0001219039 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · Held by ARCH Venture Fund VI, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 398,257 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F1 · price: The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

F5 · derivative.exercise_date: These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

F6 · derivative.expiration_date: Not applicable.

F2 · ownership.nature: The shares are held of record by ARCH Venture Fund VI, L.P. ("ARCH Fund VI"). The sole general partner of ARCH Fund VI is ARCH Venture Partners VI, L.P. ("ARCH Partners VI"), which may be deemed to beneficially own the shares held by ARCH Fund VI. The sole general partner of ARCH Partners VI is ARCH Venture Partners VI, LLC ("ARCH VI LLC"), which may be deemed to beneficially own the shares held by ARCH Fund VI. ARCH Partners VI and ARCH VI LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. As a managing director of ARCH VI LLC, the Reporting Person may be deemed to beneficially own the shares held by ARCH Fund VI. The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-17-073155 · a4.xml · nonDerivative · entry 7

CRANDELL KEITH · CIK 0001219039 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · Held by ARCH Venture Fund VIII Overage, L.P.

Disclosed balance after: 1,537,684

F4 · shares: Reflects shares purchased in the Issuer's initial public offering.

F3 · ownership.nature: The shares are held of record by ARCH Venture Fund VIII Overage, L.P. ("ARCH Fund Overage"). The sole general partner of ARCH Fund Overage is ARCH Venture Partners VIII, LLC ("ARCH VIII LLC"), which may be deemed to beneficially own the shares held by ARCH Fund Overage. ARCH VIII LLC disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein. As a managing director of ARCH VIII LLC, the Reporting Person may be deemed to beneficially own the shares held by ARCH Fund Overage. The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.