MASS

SEC source: 0001562180-21-005812 · primarydocument.xml · nonDerivative · entry 1

Brown Christopher D. · CIK 0001836988 · Chief Technology Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,045,227

F1 · kind: Represents sales effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $35.03 to $36.02, inclusive. The reporting person undertakes to provide to 908 Devices Inc., any security holder of 908 Devices Inc., 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 this footnote.

SEC source: 0001562180-21-005631 · primarydocument.xml · derivative · entry 7

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 84,504

Underlying: Common Stock · 84,643 shares

Expires 2027-04-26

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.

F3 · derivative.exercise_date: Twenty-five percent of the shares underlying the option became vested and exercisable on January 8, 2018 and the remaining 75% of the shares underlying the option become vested and exercisable in substantially equal monthly installments over the 36 months following January 8, 2018, subject to the reporting person's continued service through the applicable vesting date.

SEC source: 0001562180-21-005631 · primarydocument.xml · derivative · entry 6

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 84,643

Underlying: Common Stock · 85,779 shares

Expires 2027-04-26

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.

F3 · derivative.exercise_date: Twenty-five percent of the shares underlying the option became vested and exercisable on January 8, 2018 and the remaining 75% of the shares underlying the option become vested and exercisable in substantially equal monthly installments over the 36 months following January 8, 2018, subject to the reporting person's continued service through the applicable vesting date.

SEC source: 0001562180-21-005631 · primarydocument.xml · derivative · entry 5

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 85,779

Underlying: Common Stock · 86,507 shares

Expires 2027-04-26

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.

F3 · derivative.exercise_date: Twenty-five percent of the shares underlying the option became vested and exercisable on January 8, 2018 and the remaining 75% of the shares underlying the option become vested and exercisable in substantially equal monthly installments over the 36 months following January 8, 2018, subject to the reporting person's continued service through the applicable vesting date.

SEC source: 0001562180-21-005631 · primarydocument.xml · nonDerivative · entry 4

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 35,000

F1 · kind: Represents sales effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $34.90 to $35.18, inclusive. The reporting person undertakes to provide to 908 Devices Inc., any security holder of 908 Devices Inc., 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 this footnote.

SEC source: 0001562180-21-005631 · primarydocument.xml · nonDerivative · entry 3

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 37,003

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.

SEC source: 0001562180-21-005631 · primarydocument.xml · nonDerivative · entry 2

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 36,864

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.

SEC source: 0001562180-21-005631 · primarydocument.xml · nonDerivative · entry 1

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 35,728

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.

SEC source: 0001562180-21-005566 · primarydocument.xml · derivative · entry 23

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 86,507

Underlying: Common Stock · 87,407 shares

Expires 2027-04-26

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.

F7 · derivative.exercise_date: Twenty-five percent of the shares underlying the option became vested and exercisable on January 8, 2018 and the remaining 75% of the shares underlying the option become vested and exercisable in substantially equal monthly installments over the 36 months following January 8, 2018, subject to the reporting person's continued service through the applicable vesting date.

SEC source: 0001562180-21-005566 · primarydocument.xml · derivative · entry 22

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 87,407

Underlying: Common Stock · 88,107 shares

Expires 2027-04-26

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.

F7 · derivative.exercise_date: Twenty-five percent of the shares underlying the option became vested and exercisable on January 8, 2018 and the remaining 75% of the shares underlying the option become vested and exercisable in substantially equal monthly installments over the 36 months following January 8, 2018, subject to the reporting person's continued service through the applicable vesting date.

SEC source: 0001562180-21-005566 · primarydocument.xml · nonDerivative · entry 14

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 35,000

F1 · kind: Represents sales effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.

F6 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $34.90 to $35.01, inclusive. The reporting person undertakes to provide to 908 Devices Inc., any security holder of 908 Devices Inc., 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 this footnote.

SEC source: 0001562180-21-005566 · primarydocument.xml · nonDerivative · entry 13

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 36,600

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.

SEC source: 0001562180-21-005566 · primarydocument.xml · nonDerivative · entry 12

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 35,700

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.

SEC source: 0001562180-21-005566 · primarydocument.xml · derivative · entry 21

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 88,107

Underlying: Common Stock · 94,368 shares

Expires 2027-04-26

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.

F7 · derivative.exercise_date: Twenty-five percent of the shares underlying the option became vested and exercisable on January 8, 2018 and the remaining 75% of the shares underlying the option become vested and exercisable in substantially equal monthly installments over the 36 months following January 8, 2018, subject to the reporting person's continued service through the applicable vesting date.

SEC source: 0001562180-21-005566 · primarydocument.xml · derivative · entry 20

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 94,368

Underlying: Common Stock · 98,185 shares

Expires 2027-04-26

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.

F7 · derivative.exercise_date: Twenty-five percent of the shares underlying the option became vested and exercisable on January 8, 2018 and the remaining 75% of the shares underlying the option become vested and exercisable in substantially equal monthly installments over the 36 months following January 8, 2018, subject to the reporting person's continued service through the applicable vesting date.

SEC source: 0001562180-21-005566 · primarydocument.xml · nonDerivative · entry 11

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 35,000

F1 · kind: Represents sales effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $34.90 to $35.08, inclusive. The reporting person undertakes to provide to 908 Devices Inc., any security holder of 908 Devices Inc., 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 this footnote.

SEC source: 0001562180-21-005566 · primarydocument.xml · nonDerivative · entry 10

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 45,078

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.

SEC source: 0001562180-21-005566 · primarydocument.xml · nonDerivative · entry 9

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 38,817

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.

SEC source: 0001562180-21-005566 · primarydocument.xml · derivative · entry 19

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 98,185

Underlying: Common Stock · 110,185 shares

Expires 2027-04-26

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.

F7 · derivative.exercise_date: Twenty-five percent of the shares underlying the option became vested and exercisable on January 8, 2018 and the remaining 75% of the shares underlying the option become vested and exercisable in substantially equal monthly installments over the 36 months following January 8, 2018, subject to the reporting person's continued service through the applicable vesting date.

SEC source: 0001562180-21-005566 · primarydocument.xml · derivative · entry 18

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 110,185

Underlying: Common Stock · 112,804 shares

Expires 2027-04-26

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.

F7 · derivative.exercise_date: Twenty-five percent of the shares underlying the option became vested and exercisable on January 8, 2018 and the remaining 75% of the shares underlying the option become vested and exercisable in substantially equal monthly installments over the 36 months following January 8, 2018, subject to the reporting person's continued service through the applicable vesting date.

SEC source: 0001562180-21-005566 · primarydocument.xml · derivative · entry 17

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 112,804

Underlying: Common Stock · 118,804 shares

Expires 2027-04-26

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.

F7 · derivative.exercise_date: Twenty-five percent of the shares underlying the option became vested and exercisable on January 8, 2018 and the remaining 75% of the shares underlying the option become vested and exercisable in substantially equal monthly installments over the 36 months following January 8, 2018, subject to the reporting person's continued service through the applicable vesting date.

SEC source: 0001562180-21-005566 · primarydocument.xml · derivative · entry 16

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 118,804

Underlying: Common Stock · 120,504 shares

Expires 2027-04-26

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.

F7 · derivative.exercise_date: Twenty-five percent of the shares underlying the option became vested and exercisable on January 8, 2018 and the remaining 75% of the shares underlying the option become vested and exercisable in substantially equal monthly installments over the 36 months following January 8, 2018, subject to the reporting person's continued service through the applicable vesting date.

SEC source: 0001562180-21-005566 · primarydocument.xml · derivative · entry 15

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 120,504

Underlying: Common Stock · 123,504 shares

Expires 2027-04-26

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.

F7 · derivative.exercise_date: Twenty-five percent of the shares underlying the option became vested and exercisable on January 8, 2018 and the remaining 75% of the shares underlying the option become vested and exercisable in substantially equal monthly installments over the 36 months following January 8, 2018, subject to the reporting person's continued service through the applicable vesting date.

SEC source: 0001562180-21-005566 · primarydocument.xml · nonDerivative · entry 8

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 35,000

F1 · kind: Represents sales effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $34.69 to $35.00, inclusive. The reporting person undertakes to provide to 908 Devices Inc., any security holder of 908 Devices Inc., 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 this footnote.

SEC source: 0001562180-21-005566 · primarydocument.xml · nonDerivative · entry 7

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 47,135

F1 · kind: Represents sales effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $33.69 to $34.68, inclusive. The reporting person undertakes to provide to 908 Devices Inc., any security holder of 908 Devices Inc., 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 this footnote.

SEC source: 0001562180-21-005566 · primarydocument.xml · nonDerivative · entry 6

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 50,435

F1 · kind: Represents sales effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $32.69 to $33.59, inclusive. The reporting person undertakes to provide to 908 Devices Inc., any security holder of 908 Devices Inc., 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 this footnote.

SEC source: 0001562180-21-005566 · primarydocument.xml · nonDerivative · entry 5

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 60,319

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.

SEC source: 0001562180-21-005566 · primarydocument.xml · nonDerivative · entry 4

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 48,319

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.

SEC source: 0001562180-21-005566 · primarydocument.xml · nonDerivative · entry 3

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 45,700

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.

SEC source: 0001562180-21-005566 · primarydocument.xml · nonDerivative · entry 2

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 39,700

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.

SEC source: 0001562180-21-005566 · primarydocument.xml · nonDerivative · entry 1

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 38,000

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.

SEC source: 0001562180-21-005423 · primarydocument.xml · nonDerivative · entry 5

Knopp Kevin J. · CIK 0001836523 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 776,838

F1 · kind: Represents sales effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.

SEC source: 0001562180-21-005423 · primarydocument.xml · nonDerivative · entry 4

Knopp Kevin J. · CIK 0001836523 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 788,838

F1 · kind: Represents sales effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.

SEC source: 0001562180-21-005341 · primarydocument.xml · derivative · entry 4

Kenneweg John · CIK 0001836876 · Vice President, Government

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 123,033

Underlying: Common Stock, par value $0.001 · 133,033 shares

Expires 2023-04-18

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.

F4 · derivative.exercise_date: The shares underlying the option are fully vested and immediately exercisable.

SEC source: 0001562180-21-005341 · primarydocument.xml · nonDerivative · entry 3

Kenneweg John · CIK 0001836876 · Vice President, Government

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

F1 · kind: Represents sales effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $30.77 to $31.30, inclusive. The reporting person undertakes to provide to 908 Devices Inc., any security holder of 908 Devices Inc., 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 this footnote.

SEC source: 0001562180-21-005341 · primarydocument.xml · nonDerivative · entry 2

Kenneweg John · CIK 0001836876 · Vice President, Government

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,719

F1 · kind: Represents sales effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $29.77 to $30.76, inclusive. The reporting person undertakes to provide to 908 Devices Inc., any security holder of 908 Devices Inc., 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 this footnote.

SEC source: 0001562180-21-005341 · primarydocument.xml · nonDerivative · entry 1

Kenneweg John · CIK 0001836876 · Vice President, Government

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 10,000

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.

SEC source: 0001562180-21-005423 · primarydocument.xml · nonDerivative · entry 3

Knopp Kevin J. · CIK 0001836523 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 792,838

F1 · kind: Represents sales effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $30.00 to $30.36, inclusive. The reporting person undertakes to provide to 908 Devices Inc., any security holder of 908 Devices Inc., 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 this footnote.

SEC source: 0001562180-21-005423 · primarydocument.xml · nonDerivative · entry 2

Knopp Kevin J. · CIK 0001836523 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 802,360

F1 · kind: Represents sales effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $30.38 to $31.08, inclusive. The reporting person undertakes to provide to 908 Devices Inc., any security holder of 908 Devices Inc., 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 this footnote.

SEC source: 0001562180-21-005423 · primarydocument.xml · nonDerivative · entry 1

Knopp Kevin J. · CIK 0001836523 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 808,395

F1 · kind: Represents sales effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $31.09 to $32.08, inclusive. The reporting person undertakes to provide to 908 Devices Inc., any security holder of 908 Devices Inc., 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 this footnote.

SEC source: 0001562180-21-005220 · primarydocument.xml · nonDerivative · entry 3

Brown Christopher D. · CIK 0001836988 · Chief Technology Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,053,912

F1 · kind: Represents sales effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $33.08 to $33.83, inclusive. The reporting person undertakes to provide to 908 Devices Inc., any security holder of 908 Devices Inc., 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 this footnote.

SEC source: 0001562180-21-005220 · primarydocument.xml · nonDerivative · entry 2

Brown Christopher D. · CIK 0001836988 · Chief Technology Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,059,312

F1 · kind: Represents sales effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $32.06 to $33.02, inclusive. The reporting person undertakes to provide to 908 Devices Inc., any security holder of 908 Devices Inc., 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 this footnote.

SEC source: 0001562180-21-005220 · primarydocument.xml · nonDerivative · entry 1

Brown Christopher D. · CIK 0001836988 · Chief Technology Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,064,412

F1 · kind: Represents sales effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $31.06 to $32.04, inclusive. The reporting person undertakes to provide to 908 Devices Inc., any security holder of 908 Devices Inc., 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 this footnote.

SEC source: 0001562180-21-005074 · primarydocument.xml · derivative · entry 8

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 123,504

Underlying: Common Stock · 6,000 shares

Expires 2027-04-26

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.

F4 · derivative.exercise_date: Twenty-five percent of the shares underlying the option became vested and exercisable on January 8, 2018 and the remaining 75% of the shares underlying the option become vested and exercisable in substantially equal monthly installments over the 36 months following January 8, 2018, subject to the reporting person's continued service through the applicable vesting date.

SEC source: 0001562180-21-005074 · primarydocument.xml · derivative · entry 7

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 129,504

Underlying: Common Stock · 3,000 shares

Expires 2027-04-26

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.

F4 · derivative.exercise_date: Twenty-five percent of the shares underlying the option became vested and exercisable on January 8, 2018 and the remaining 75% of the shares underlying the option become vested and exercisable in substantially equal monthly installments over the 36 months following January 8, 2018, subject to the reporting person's continued service through the applicable vesting date.

SEC source: 0001562180-21-005074 · primarydocument.xml · derivative · entry 6

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 132,504

Underlying: Common Stock · 144,504 shares

Expires 2027-04-26

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.

F4 · derivative.exercise_date: Twenty-five percent of the shares underlying the option became vested and exercisable on January 8, 2018 and the remaining 75% of the shares underlying the option become vested and exercisable in substantially equal monthly installments over the 36 months following January 8, 2018, subject to the reporting person's continued service through the applicable vesting date.

SEC source: 0001562180-21-005074 · primarydocument.xml · nonDerivative · entry 5

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 35,000

F1 · kind: Represents sales effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $32.19 to $32.83, inclusive. The reporting person undertakes to provide to 908 Devices Inc., any security holder of 908 Devices Inc., 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 this footnote.

SEC source: 0001562180-21-005074 · primarydocument.xml · nonDerivative · entry 4

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 48,893

F1 · kind: Represents sales effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $31.19 to $32.18, inclusive. The reporting person undertakes to provide to 908 Devices Inc., any security holder of 908 Devices Inc., 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 this footnote.

SEC source: 0001562180-21-005074 · primarydocument.xml · nonDerivative · entry 3

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 56,000

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.

SEC source: 0001562180-21-005074 · primarydocument.xml · nonDerivative · entry 2

Basarsky Trent A. · CIK 0001608021 · VP, Corporate Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 50,000

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.