Atlas Venture Life Science Advisors, LLC — 13F Holdings & Portfolio

CIK 1917529 · latest 13F-HR filed 2026-05-14

Atlas Venture Life Science Advisors, LLC manages $790.0M in 13F-reported U.S. long-equity assets across 6 reported positions as of its 2026-03-31 13F-HR filing. Its largest disclosed positions are KYMR (48.26%), DYN (20.95%), SION (15.20%). Quarter over quarter (versus its 2025-12-31 filing) the fund opened 0 new positions, exited 2, added to 3, and trimmed 2.

AUM is the long-equity portion reported on Form 13F-HR. Excludes short positions, cash, foreign holdings, and non-13F assets. For informational purposes only — not investment advice.

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AUM

$790.0M

Long-equity book

Holdings

6

Distinct positions

Period

2026-03-31

Filed 2026-05-14

Q/Q Activity

+0 / −2 / ↑3 / ↓2

vs 2025-12-31

Firm Profile & Key People
Name Title / Status Ownership Type

Top Adds (vs prior quarter)

  • Kymera Therapeutics, Inc.$18.7M +5.2%
  • Q32 Bio, Inc.$6.5M +93.4%
  • Korro Bio, Inc.$3.8M +41.3%
Show all 3

Top Trims

  • Disc Medicine, Inc.-$23.4M -19.5%
  • Dyne Therapeutics, Inc.-$13.1M -7.3%
Show all 2

New Positions

  • No new positions this quarter.
Show all 0

Exited Positions

  • Day One Biopharmaceuticals, Inc.$59.8M
  • Generation Bio, Co.$4.7M
Show all 2
All Holdings

Rows tagged Call or Put are options positions, not stock. Per SEC Form 13F-HR, Value shows the notional value of the underlying (shares covered × underlying price), not the option premium. Shares is the number of underlying shares covered (divide by 100 for contract count).

# Issuer Symbol CUSIP Value Weight Shares Type
1 Kymera Therapeutics, Inc. KYMR 501575104 $381.3M 48.26% 4,578,008 SH
2 Dyne Therapeutics, Inc. DYN 26818M108 $165.5M 20.95% 9,130,465 SH
3 Sionna Therapeutics, Inc. SION 829401108 $120.1M 15.20% 2,995,602 SH
4 Disc Medicine, Inc. IRON 254604101 $96.8M 12.25% 1,513,875 SH
5 Q32 Bio, Inc. QTTB 746964105 $13.4M 1.70% 2,092,106 SH
6 Korro Bio, Inc. KRRO 500946108 $12.9M 1.63% 1,137,149 SH
Filing History
Period Filed AUM Holdings Accession
2026-03-31 2026-05-14 $790.0M 6 0001104659-26-061232
2025-12-31 2026-02-13 $865.2M 8 0001104659-26-014463
2025-09-30 2025-11-13 $752.6M 9 0001104659-25-111321