Atlas Venture Life Science Advisors, LLC
Atlas Venture Life Science Advisors, LLC reported 7 US-listed holdings worth $881.3 million in its 13F for the quarter ended 30 June 2026, filed 13 August 2026. Its largest: Kymera Therapeutics Inc. (37.1%), Dyne Therapeutics Inc. (17.1%) and Sionna Therapeutics Inc (15.0%). Against the quarter before, it opened 1 position, added to 1, trimmed 3 and sold out of 0.
The 7 largest of its 7 positions, each sized by its share of the reported holdings, coloured by the change in shares against Q1 2026.
What the fund reported holding at each quarter's end; hover a bar for the number of positions
What its reported holdings returned
Held through each quarter, the holdings it reported returned +44.2% over the 7 quarters to 30 June 2026, against +30.2% for the S&P 500.
Not the fund's own return: each 13F's holdings are kept unchanged until the next one, so trades inside a quarter, dividends, cash and fees are left out. A rough guide to how its picks have done over time.
What it did on the quarter
Its positions against its 13F for the quarter to 31 March 2026; a change under 0.1% of a position counts as held
Opened 1
- Kailera Therapeutics Inc. KLRA$113.9 million
Added to 1
- Q32 Bio Inc. QTTB+625,000 shares · +30%
Trimmed 3
- Kymera Therapeutics Inc. KYMR-1.7 million shares · -38%
- Dyne Therapeutics Inc. DYN-2.3 million shares · -26%
- Korro Bio Inc. KRRO-174,265 shares · -15%
What it holds
| Company | Shares | Value | Of its book | Change in shares |
|---|---|---|---|---|
| Kymera Therapeutics Inc. KYMR | 2.8M | $326.5 million | 37.05% | -1.7M |
| Dyne Therapeutics Inc. DYN | 6.8M | $151.0 million | 17.14% | -2.3M |
| Sionna Therapeutics Inc SION | 3.0M | $131.8 million | 14.95% | no change |
| Kailera Therapeutics Inc. KLRA | 5.2M | $113.9 million | 12.93% | new |
| Disc Medicine Inc. IRON | 1.5M | $110.7 million | 12.56% | no change |
| Q32 Bio Inc. QTTB | 2.7M | $34.6 million | 3.93% | +625.0K |
| Korro Bio Inc. KRRO | 962.9K | $12.7 million | 1.44% | -174.3K |