REPLIGEN CORP — Director's Dealing 2020

May 20, 2020

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: REPLIGEN CORP (RGEN)
CIK: 0000730272
Period of Report: 2020-05-13

Reporting Person: DAWES KAREN A (Director)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2020-05-13	Common Stock	A	722	$0.00	Acquired	121556	Direct
2020-05-18	Common Stock	S	712	$135.76	Disposed	120844	Direct
2020-05-18	Common Stock	S	160	$136.92	Disposed	120684	Direct
2020-05-18	Common Stock	S	269	$138.60	Disposed	120415	Direct
2020-05-18	Common Stock	S	122	$139.32	Disposed	120293	Direct
2020-05-18	Common Stock	S	180	$140.62	Disposed	120113	Direct
2020-05-18	Common Stock	S	77	$141.45	Disposed	120036	Direct
2020-05-18	Common Stock	S	80	$142.45	Disposed	119956	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2020-05-13	Stock Option (Right to Buy)	$128.18	A	1761	Acquired	2030-05-13	Common Stock (1761)	Direct

Footnotes

F1: Ms. Dawes was awarded 722 restricted stock units. Each restricted stock unit represents a contingent right to receive one share of Repligen Corporation's Common Stock. The restricted stock units vest on May 13, 2021. The restricted stock units may be settled only by delivering shares of Repligen Corporation's Common Stock, and thus, the grant is being reported in Table I as allowed per SEC guidance.

F2: Sale of common stock was effected pursuant to a 10(b)5-1 trading plan adopted on February 19, 2020.

F3: $135.76 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $135.26 to $136.19, 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 range.

F4: $138.60 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $137.94 to $138.84, 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 range.

F5: $139.32 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $139.11 to $139.44, 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 range.

F6: $140.62 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $140.21 to $140.89, 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 range.

F7: $141.45 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $141.42 to $142.01, 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 range.

F8: Award vests in full one year from grant date on May 13, 2021.