Beam Therapeutics Inc. — Director's Dealing 2021

Jul 2, 2021

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Beam Therapeutics Inc. (BEAM)
CIK: 0001745999
Period of Report: 2021-06-30

Reporting Person: ARCH Venture Partners IX, LLC (10% Owner)
Reporting Person: ARCH Venture Partners IX, L.P. (10% Owner)
Reporting Person: ARCH Venture Partners IX Overage, L.P. (10% Owner)
Reporting Person: ARCH Venture Fund IX, L.P. (10% Owner)
Reporting Person: ARCH Venture Fund IX Overage, L.P. (10% Owner)
Reporting Person: CRANDELL KEITH (10% Owner)
Reporting Person: BYBEE CLINTON (10% Owner)
Reporting Person: NELSEN ROBERT (10% Owner)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2021-06-30	Common Stock	J	200000	—	Disposed	2921520	Indirect
2021-06-30	Common Stock	J	200000	—	Disposed	2921519	Indirect
2021-06-30	Common Stock	J	2555	—	Acquired	15328	Direct
2021-06-30	Common Stock	J	811	—	Acquired	4867	Direct
2021-06-30	Common Stock	J	4686	—	Acquired	28111	Direct

Footnotes

F1: Distribution of Common Stock held by a limited partnership to its partners for no consideration.

F2: These shares are directly held by ARCH Venture Fund IX, L.P. ("ARCH IX"). ARCH Venture Partners IX, L.P. ("GPLP"), as the sole general partner of ARCH IX, may be deemed to beneficially own the shares held by ARCH IX. ARCH Venture Partners IX, LLC ("GPLLC"), as the sole general partner of GPLP, may be deemed to beneficially own the shares held by ARCH IX. As managing directors of GPLLC, each of Keith Crandell, Robert Nelsen and Clinton Bybee (the "ARCH Managing Directors"), may be deemed to beneficially own the shares held by ARCH IX. Each of GPLP, GPLLC and the ARCH Managing Directors disclaims beneficial ownership of the securities reported herein, except to the extent of their pecuniary interest therein, if any.

F3: These shares are directly held by ARCH Venture Fund IX Overage, L.P. ("ARCH Overage"). ARCH Venture Partners IX Overage, L.P. ("Overage GPLP"), as the sole general partner of ARCH Overage, may be deemed to beneficially own the shares held by ARCH Overage. GPLLC, as the sole general partner of Overage GPLP, may be deemed to beneficially own the shares held by ARCH Overage. As managing directors of GPLLC, each of the ARCH Managing Directors may be deemed to beneficially own the shares held by ARCH Overage. Each of Overage GPLP, GPLLC and the ARCH Managing Directors disclaims beneficial ownership of the securities reported herein, except to the extent of their pecuniary interest therein, if any.

F4: Change from indirect to direct ownership of shares previously reported as beneficially owned by the Reporting Person.

F5: Shares held directly by Crandell.

F6: Shares held directly by Bybee.

F7: Shares held directly by Nelsen.