Atlas Venture Life Science Advisors, LLC 13F holdings
Atlas Venture Life Science Advisors, LLC reported 7 positions with a total reported value of $881.3M as of 2026-06-30, in its 13F for Q2 2026, filed 2026-08-13. Top holdings by reported value: KYMR Kymera Therapeutics, Inc. (37.1%), DYN Dyne Therapeutics, Inc. (17.1%), SION Sionna Therapeutics, Inc. (15.0%), KLRA Kailera Therapeutics, Inc. (12.9%), IRON Disc Medicine, Inc. (12.6%). Against 2026-03-31 it opened 1 new position and exited 0. Next 13F due by 2026-11-14, the legal deadline 45 days after the quarter ending 2026-09-30.
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Top holdings
7 largest of 7 positions · reported value as of 2026-06-30
| Holding | Shares | Reported value | % of portfolio |
|---|---|---|---|
| KYMR Kymera Therapeutics, Inc. | 2,847,541 | $326.5M | 37.1% |
| DYN Dyne Therapeutics, Inc. | 6,800,099 | $151.0M | 17.1% |
| SION Sionna Therapeutics, Inc. | 2,995,602 | $131.8M | 15.0% |
| KLRA Kailera Therapeutics, Inc. | 5,171,282 | $113.9M | 12.9% |
| IRON Disc Medicine, Inc. | 1,513,875 | $110.7M | 12.6% |
| QTTB Q32 Bio, Inc. | 2,717,106 | $34.6M | 3.9% |
| KRRO Korro Bio, Inc. | 962,884 | $12.7M | 1.4% |
SEC FORM 13F · Q2 2026 · VALUES AS REPORTED, NOT PRICES
New positions this quarter
Held at 2026-06-30, not at 2026-03-31 · 1 in all · reported value as of 2026-06-30
| Holding | Shares | Reported value | % of portfolio |
|---|---|---|---|
| KLRA Kailera Therapeutics, Inc. | 5,171,282 | $113.9M | 12.9% |
Sold out
Held at 2026-03-31, gone by 2026-06-30 · 0 in all · reported value as of 2026-03-31
No positions were sold out.
Biggest increases and decreases
Positions held at both quarter ends, by change in shares · reported value as of 2026-06-30
Increases
| Holding | Shares 2026-03-31 | Shares 2026-06-30 | Change | Reported value |
|---|---|---|---|---|
| QTTB Q32 Bio, Inc. | 2,092,106 | 2,717,106 | +29.9% | $34.6M |
Decreases
| Holding | Shares 2026-03-31 | Shares 2026-06-30 | Change | Reported value |
|---|---|---|---|---|
| KYMR Kymera Therapeutics, Inc. | 4,578,008 | 2,847,541 | -37.8% | $326.5M |
| DYN Dyne Therapeutics, Inc. | 9,130,465 | 6,800,099 | -25.5% | $151.0M |
| KRRO Korro Bio, Inc. | 1,137,149 | 962,884 | -15.3% | $12.7M |
CIK 1917529 · 13F FILINGS ON EDGAR · INFORMATIONAL ONLY
