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Atlas Venture Life Science Advisors, LLC

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13F filer, CIK 1917529, CAMBRIDGE, MA

Atlas Venture Life Science Advisors, LLC reported $881,289,158 across 7 holdings for the quarter ended 2026-06-30, in a 13F-HR filed 2026-08-13.

Filed (acceptance time not in the bulk data set), ingested 13F-HR 0001104659-26-095933

Period
2026-06-30
Reported value
$881M
Holdings
7
Top 10 weight
100%
New
1
Sold out
0

Largest buys vs the previous quarter

SecurityShares changeApprox. value
KLRAnew+5,171,282$114M
QTTBadded+625,000$7.96M

Ranked by the share change valued at this quarter's implied price (value over shares in the 13F). A position sold out is valued at the previous quarter's price, its last report.

Largest sells vs the previous quarter

SecurityShares changeApprox. value
KYMRreduced-1,730,467-$198M
DYNreduced-2,330,366-$51.8M
KRROreduced-174,265-$2.3M

Ranked by the share change valued at this quarter's implied price (value over shares in the 13F). A position sold out is valued at the previous quarter's price, its last report.

Holdings, Q2 2026

Share positions as resolved from 13F-HR 0001104659-26-095933, largest first. % of portfolio is the value over $881,289,158, the sum of the share positions whose value is usable for ratios (method).

SecurityHistorySharesValue% of portfolioChangeLatest eventTimeline
KYMRKYMERA THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q3: 4,896,462 shares; 2024Q4: 4,896,462 shares; 2025Q1: 4,896,462 shares; 2025Q2: 4,896,462 shares; 2025Q3: 4,896,462 shares; 2025Q4: 4,659,874 shares; 2026Q1: 4,578,008 shares; 2026Q2: 2,847,541 shares 2,847,541$327M37.05%-1,730,467Timeline
DYNDYNE THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q3: 8,020,136 shares; 2024Q4: 8,019,354 shares; 2025Q1: 9,130,465 shares; 2025Q2: 9,130,465 shares; 2025Q3: 9,130,465 shares; 2025Q4: 9,130,465 shares; 2026Q1: 9,130,465 shares; 2026Q2: 6,800,099 shares 6,800,099$151M17.14%-2,330,366Timeline
SIONSIONNA THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q3: not reported; 2024Q4: not reported; 2025Q1: 3,694,020 shares; 2025Q2: 3,694,020 shares; 2025Q3: 3,615,527 shares; 2025Q4: 2,995,602 shares; 2026Q1: 2,995,602 shares; 2026Q2: 2,995,602 shares 2,995,602$132M14.95%0Timeline
KLRAKAILERA THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q3: not reported; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: not reported; 2025Q4: not reported; 2026Q1: not reported; 2026Q2: 5,171,282 shares 5,171,282$114M12.93%newTimeline
IRONDISC MEDICINE INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q3: 2,509,456 shares; 2024Q4: 2,509,456 shares; 2025Q1: 2,384,456 shares; 2025Q2: 2,384,456 shares; 2025Q3: 2,142,617 shares; 2025Q4: 1,513,875 shares; 2026Q1: 1,513,875 shares; 2026Q2: 1,513,875 shares 1,513,875$111M12.56%0Timeline
QTTBQ32 BIO INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q3: 2,092,106 shares; 2024Q4: 2,092,106 shares; 2025Q1: 2,092,106 shares; 2025Q2: 2,092,106 shares; 2025Q3: 2,092,106 shares; 2025Q4: 2,092,106 shares; 2026Q1: 2,092,106 shares; 2026Q2: 2,717,106 shares 2,717,106$34.6M3.93%+625,000Timeline
KRROKORRO BIO INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q3: 1,137,149 shares; 2024Q4: 1,137,149 shares; 2025Q1: 1,137,149 shares; 2025Q2: 1,137,149 shares; 2025Q3: 1,137,149 shares; 2025Q4: 1,137,149 shares; 2026Q1: 1,137,149 shares; 2026Q2: 962,884 shares 962,884$12.7M1.44%-174,265Timeline

How Q2 2026 was built

Available 13F filings of this filer for the quarter and their roles: the base report is the latest original or restatement, NEW HOLDINGS amendments filed after it are added (method).

FilingRoleAmendmentFiledAcceptedIngested
13F-HR 0001104659-26-095933 base2026-08-13acceptance time not in the bulk data set