CDLX

SEC source: 0000899243-20-002427 · doc4.xml · nonDerivative · entry 8

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F6 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $86.17 to $86.51, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (6) to this Form 4.

F7 · ownership.nature: The reportable securities are owned directly by PVPE V. PVM V is the general partner of PVPE V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPE V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002427 · doc4.xml · nonDerivative · entry 7

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 29

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $85.15 to $86.14, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (5) to this Form 4.

F7 · ownership.nature: The reportable securities are owned directly by PVPE V. PVM V is the general partner of PVPE V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPE V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002427 · doc4.xml · nonDerivative · entry 6

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 234

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $84.13 to $85.12, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (4) to this Form 4.

F7 · ownership.nature: The reportable securities are owned directly by PVPE V. PVM V is the general partner of PVPE V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPE V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002427 · doc4.xml · nonDerivative · entry 5

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 303

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $83.13 to $84.12, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (2) to this Form 4.

F7 · ownership.nature: The reportable securities are owned directly by PVPE V. PVM V is the general partner of PVPE V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPE V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002427 · doc4.xml · nonDerivative · entry 4

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F6 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $86.17 to $86.51, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (6) to this Form 4.

F3 · ownership.nature: The reportable securities are owned directly by PVP V. Polaris Venture Management Co. V, L.L.C. ("PVM V") is the general partner of PVP V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Jonathan A. Flint ("Flint") and Terrance G. McGuire ("McGuire") are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVP V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002427 · doc4.xml · nonDerivative · entry 3

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,510

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $85.15 to $86.14, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (5) to this Form 4.

F3 · ownership.nature: The reportable securities are owned directly by PVP V. Polaris Venture Management Co. V, L.L.C. ("PVM V") is the general partner of PVP V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Jonathan A. Flint ("Flint") and Terrance G. McGuire ("McGuire") are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVP V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002427 · doc4.xml · nonDerivative · entry 2

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 12,046

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $84.13 to $85.12, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (4) to this Form 4.

F3 · ownership.nature: The reportable securities are owned directly by PVP V. Polaris Venture Management Co. V, L.L.C. ("PVM V") is the general partner of PVP V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Jonathan A. Flint ("Flint") and Terrance G. McGuire ("McGuire") are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVP V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002427 · doc4.xml · nonDerivative · entry 1

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 15,562

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $83.13 to $84.12, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (2) to this Form 4.

F3 · ownership.nature: The reportable securities are owned directly by PVP V. Polaris Venture Management Co. V, L.L.C. ("PVM V") is the general partner of PVP V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Jonathan A. Flint ("Flint") and Terrance G. McGuire ("McGuire") are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVP V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002309 · doc4.xml · nonDerivative · entry 12

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 177

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $86.38 to $86.55, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (5) to this Form 4.

F8 · ownership.nature: The reportable securities are owned directly by PVPSFF V. PVM V is the general partner of PVPSFF V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPSFF V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002309 · doc4.xml · nonDerivative · entry 11

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 179

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $85.38 to $86.37, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (4) to this Form 4.

F8 · ownership.nature: The reportable securities are owned directly by PVPSFF V. PVM V is the general partner of PVPSFF V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPSFF V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002309 · doc4.xml · nonDerivative · entry 10

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 230

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $84.38 to $85.37, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (2) to this Form 4.

F8 · ownership.nature: The reportable securities are owned directly by PVPSFF V. PVM V is the general partner of PVPSFF V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPSFF V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002309 · doc4.xml · nonDerivative · entry 9

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 121

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $86.38 to $86.55, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (5) to this Form 4.

F7 · ownership.nature: The reportable securities are owned directly by PVPFF V. PVM V is the general partner of PVPFF V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPFF V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002309 · doc4.xml · nonDerivative · entry 8

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 122

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $85.38 to $86.37, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (4) to this Form 4.

F7 · ownership.nature: The reportable securities are owned directly by PVPFF V. PVM V is the general partner of PVPFF V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPFF V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002309 · doc4.xml · nonDerivative · entry 7

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 157

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $84.38 to $85.37, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (2) to this Form 4.

F7 · ownership.nature: The reportable securities are owned directly by PVPFF V. PVM V is the general partner of PVPFF V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPFF V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002309 · doc4.xml · nonDerivative · entry 6

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 344

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $86.38 to $86.55, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (5) to this Form 4.

F6 · ownership.nature: The reportable securities are owned directly by PVPE V. PVM V is the general partner of PVPE V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPE V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002309 · doc4.xml · nonDerivative · entry 5

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 348

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $85.38 to $86.37, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (4) to this Form 4.

F6 · ownership.nature: The reportable securities are owned directly by PVPE V. PVM V is the general partner of PVPE V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPE V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002309 · doc4.xml · nonDerivative · entry 4

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 448

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $84.38 to $85.37, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (2) to this Form 4.

F6 · ownership.nature: The reportable securities are owned directly by PVPE V. PVM V is the general partner of PVPE V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPE V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002309 · doc4.xml · nonDerivative · entry 3

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 17,685

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $86.38 to $86.55, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (5) to this Form 4.

F3 · ownership.nature: The reportable securities are owned directly by PVP V. Polaris Venture Management Co. V, L.L.C. ("PVM V") is the general partner of PVP V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Jonathan A. Flint ("Flint") and Terrance G. McGuire ("McGuire") are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVP V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002309 · doc4.xml · nonDerivative · entry 2

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 17,878

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $85.38 to $86.37, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (4) to this Form 4.

F3 · ownership.nature: The reportable securities are owned directly by PVP V. Polaris Venture Management Co. V, L.L.C. ("PVM V") is the general partner of PVP V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Jonathan A. Flint ("Flint") and Terrance G. McGuire ("McGuire") are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVP V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002309 · doc4.xml · nonDerivative · entry 1

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 22,991

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $84.38 to $85.37, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (2) to this Form 4.

F3 · ownership.nature: The reportable securities are owned directly by PVP V. Polaris Venture Management Co. V, L.L.C. ("PVM V") is the general partner of PVP V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Jonathan A. Flint ("Flint") and Terrance G. McGuire ("McGuire") are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVP V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001666071-20-000016 · wf-form4_158016666633794.xml · nonDerivative · entry 7

Grimes Scott D. · CIK 0001617486 · Director · Chief Executive Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 387,203

F4 · kind: These sales were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 5, 2018, as amended May 14, 2019.

F9 · price: The price reported is a weighted average sales price. These shares were sold in multiple transactions at prices ranging from $87.79 to $87.99, inclusive.

SEC source: 0001666071-20-000016 · wf-form4_158016666633794.xml · nonDerivative · entry 6

Grimes Scott D. · CIK 0001617486 · Director · Chief Executive Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 387,503

F4 · kind: These sales were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 5, 2018, as amended May 14, 2019.

F8 · price: The price reported is a weighted average sales price. These shares were sold in multiple transactions at prices ranging from $86.67 to $87.64, inclusive.

SEC source: 0001666071-20-000016 · wf-form4_158016666633794.xml · nonDerivative · entry 5

Grimes Scott D. · CIK 0001617486 · Director · Chief Executive Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 388,595

F4 · kind: These sales were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 5, 2018, as amended May 14, 2019.

F7 · price: The price reported is a weighted average sales price. These shares were sold in multiple transactions at prices ranging from $85.66 to $86.60, inclusive.

SEC source: 0001666071-20-000016 · wf-form4_158016666633794.xml · nonDerivative · entry 4

Grimes Scott D. · CIK 0001617486 · Director · Chief Executive Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 390,495

F4 · kind: These sales were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 5, 2018, as amended May 14, 2019.

F6 · price: The price reported is a weighted average sales price. These shares were sold in multiple transactions at prices ranging from $84.66 to $85.65, inclusive.

SEC source: 0001666071-20-000016 · wf-form4_158016666633794.xml · nonDerivative · entry 3

Grimes Scott D. · CIK 0001617486 · Director · Chief Executive Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 394,395

F4 · kind: These sales were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 5, 2018, as amended May 14, 2019.

F5 · price: The price reported is a weighted average sales price. These shares were sold in multiple transactions at prices ranging from $83.60 to $84.32, inclusive.

SEC source: 0001666071-20-000018 · wf-form4_158025118636869.xml · derivative · entry 11

Evans David Thomas · CIK 0001730451 · Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 11,719

Underlying: Common Stock · 25,781 shares

Expires 2027-07-07

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 · kind: These transactions were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 23, 2019.

F9 · derivative.exercise_date: This option becomes exercisable with respect to one quarter (1/4) of the shares of stock subject to this option on April 1, 2018 (the "Initial Vesting Date"). The option becomes exercisable in respect of the remaining shares in thirty-six (36) equal monthly installments commencing one (1) month after the Initial Vesting Date, provided the Reporting Person continuously provides service to the Issuer through each vesting period.

SEC source: 0001666071-20-000018 · wf-form4_158025118636869.xml · derivative · entry 10

Evans David Thomas · CIK 0001730451 · Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 8,594

Underlying: Common Stock · 28,906 shares

Expires 2026-12-06

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 · kind: These transactions were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 23, 2019.

F8 · derivative.exercise_date: This option became exercisable with respect to one quarter (1/4) of the shares of stock subject to this option on December 6, 2017 (the "Initial Vesting Date"). The options becomes exercisable in respect of the remaining shares in thirty-six (36) equal monthly installments commencing one (1) month after the Initial Vesting Date, provided the Reporting Person continuously provides service to the Issuer through each vesting period.

SEC source: 0001666071-20-000018 · wf-form4_158025118636869.xml · derivative · entry 9

Evans David Thomas · CIK 0001730451 · Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 6,250

Underlying: Common Stock · 53,757 shares

Expires 2026-08-02

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 · kind: These transactions were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 23, 2019.

F7 · derivative.exercise_date: This option became exercisable with respect to one quarter (1/4) of the shares of stock subject to this option on June 15, 2017 (the "Initial Vesting Date"). The option becomes exercisable in respect of the remaining shares in thirty-six (36) equal monthly installments commencing one (1) month after the Initial Vesting Date, provided the Reporting Person continuously provides service to the Issuer through each vesting period.

SEC source: 0001666071-20-000018 · wf-form4_158025118636869.xml · nonDerivative · entry 8

Evans David Thomas · CIK 0001730451 · Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 30,810

F1 · kind: These transactions were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 23, 2019.

F6 · price: The price reported is a weighted average sales price. These shares were sold in multiple transactions at prices ranging from $87.44 to $88.11, inclusive.

SEC source: 0001666071-20-000018 · wf-form4_158025118636869.xml · nonDerivative · entry 7

Evans David Thomas · CIK 0001730451 · Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 36,587

F1 · kind: These transactions were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 23, 2019.

F5 · price: The price reported is a weighted average sales price. These shares were sold in multiple transactions at prices ranging from $86.44 to $87.43, inclusive.

SEC source: 0001666071-20-000018 · wf-form4_158025118636869.xml · nonDerivative · entry 6

Evans David Thomas · CIK 0001730451 · Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 46,524

F1 · kind: These transactions were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 23, 2019.

F4 · price: The price reported is a weighted average sales price. These shares were sold in multiple transactions at prices ranging from $85.44 to $86.40, inclusive.

SEC source: 0001666071-20-000018 · wf-form4_158025118636869.xml · nonDerivative · entry 5

Evans David Thomas · CIK 0001730451 · Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 71,159

F1 · kind: These transactions were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 23, 2019.

F3 · price: The price reported is a weighted average sales price. These shares were sold in multiple transactions at prices ranging from $84.44 to $85.43, inclusive.

SEC source: 0001666071-20-000018 · wf-form4_158025118636869.xml · nonDerivative · entry 4

Evans David Thomas · CIK 0001730451 · Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 101,584

F1 · kind: These transactions were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 23, 2019.

F2 · price: The price reported is a weighted average sales price. These shares were sold in multiple transactions at prices ranging from $83.43 to $84.42, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (2), (3), (4), (5) and (6) to this Form 4.

SEC source: 0001666071-20-000018 · wf-form4_158025118636869.xml · nonDerivative · entry 3

Evans David Thomas · CIK 0001730451 · Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 130,680

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 · kind: These transactions were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 23, 2019.

SEC source: 0001666071-20-000018 · wf-form4_158025118636869.xml · nonDerivative · entry 2

Evans David Thomas · CIK 0001730451 · Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 104,899

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 · kind: These transactions were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 23, 2019.

SEC source: 0001666071-20-000018 · wf-form4_158025118636869.xml · nonDerivative · entry 1

Evans David Thomas · CIK 0001730451 · Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 75,993

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 · kind: These transactions were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 23, 2019.

SEC source: 0000899243-20-002307 · doc4.xml · nonDerivative · entry 20

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 317

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F7 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $87.48 to $88.075, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (7) to this Form 4.

F10 · ownership.nature: The reportable securities are owned directly by PVPSFF V. PVM V is the general partner of PVPSFF V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPSFF V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002307 · doc4.xml · nonDerivative · entry 19

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 341

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F6 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $86.47 to $87.44, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (6) to this Form 4.

F10 · ownership.nature: The reportable securities are owned directly by PVPSFF V. PVM V is the general partner of PVPSFF V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPSFF V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002307 · doc4.xml · nonDerivative · entry 18

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 375

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $85.47 to $86.46, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (5) to this Form 4.

F10 · ownership.nature: The reportable securities are owned directly by PVPSFF V. PVM V is the general partner of PVPSFF V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPSFF V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002307 · doc4.xml · nonDerivative · entry 17

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 444

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $84.47 to $85.46, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (4) to this Form 4.

F10 · ownership.nature: The reportable securities are owned directly by PVPSFF V. PVM V is the general partner of PVPSFF V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPSFF V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002307 · doc4.xml · nonDerivative · entry 16

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 563

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $83.43 to $84.41, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (2) to this Form 4.

F10 · ownership.nature: The reportable securities are owned directly by PVPSFF V. PVM V is the general partner of PVPSFF V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPSFF V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002307 · doc4.xml · nonDerivative · entry 15

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 216

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F7 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $87.48 to $88.075, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (7) to this Form 4.

F9 · ownership.nature: The reportable securities are owned directly by PVPFF V. PVM V is the general partner of PVPFF V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPFF V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002307 · doc4.xml · nonDerivative · entry 14

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 233

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F6 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $86.47 to $87.44, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (6) to this Form 4.

F9 · ownership.nature: The reportable securities are owned directly by PVPFF V. PVM V is the general partner of PVPFF V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPFF V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002307 · doc4.xml · nonDerivative · entry 13

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 256

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $85.47 to $86.46, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (5) to this Form 4.

F9 · ownership.nature: The reportable securities are owned directly by PVPFF V. PVM V is the general partner of PVPFF V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPFF V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002307 · doc4.xml · nonDerivative · entry 12

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 302

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $84.47 to $85.46, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (4) to this Form 4.

F9 · ownership.nature: The reportable securities are owned directly by PVPFF V. PVM V is the general partner of PVPFF V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPFF V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002307 · doc4.xml · nonDerivative · entry 11

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 384

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $83.43 to $84.41, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (2) to this Form 4.

F9 · ownership.nature: The reportable securities are owned directly by PVPFF V. PVM V is the general partner of PVPFF V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPFF V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002307 · doc4.xml · nonDerivative · entry 10

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 617

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F7 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $87.48 to $88.075, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (7) to this Form 4.

F8 · ownership.nature: The reportable securities are owned directly by PVPE V. PVM V is the general partner of PVPE V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPE V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002307 · doc4.xml · nonDerivative · entry 9

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 664

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F6 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $86.47 to $87.44, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (6) to this Form 4.

F8 · ownership.nature: The reportable securities are owned directly by PVPE V. PVM V is the general partner of PVPE V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPE V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002307 · doc4.xml · nonDerivative · entry 8

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 729

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $85.47 to $86.46, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (5) to this Form 4.

F8 · ownership.nature: The reportable securities are owned directly by PVPE V. PVM V is the general partner of PVPE V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPE V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0000899243-20-002307 · doc4.xml · nonDerivative · entry 7

Youngren Bryce · CIK 0001489625 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 863

F1 · kind: The sale of these shares were effected pursuant to Rule 10b5-1 trading plans adopted by each of Polaris Venture Partners V, L.P. ("PVP V"), Polaris Venture Partners Entrepreneurs' Fund V, L.P. ("PVPE V"), Polaris Venture Partners Founders' Fund V, L.P. ("PVPFF V") and Polaris Venture Partners Special Founders' Fund V, L.P. ("PVPSFF V") on December 16, 2019.

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $84.47 to $85.46, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (4) to this Form 4.

F8 · ownership.nature: The reportable securities are owned directly by PVPE V. PVM V is the general partner of PVPE V. The Reporting Person, a member of the Issuer's Board of Directors, is a member of PVM V. Each of Flint and McGuire are the managing members of PVM V. Each of Flint, McGuire and the Reporting Person, in their respective capacities with respect to PVM V, may be deemed to have shared voting and dispositive power over the shares held by PVPE V. Each of PVM V, Flint, McGuire and the Reporting Person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.