SCHEDULE 13D/A Filed 2026-05-28 Event 2026-05-26 SEC 0001628098-26-000005 →

Atlas Venture Fund X, L.P. → Q32 Bio Inc. QTTB

Stake: 3.60% Shares: 864,261 CUSIP: 746964105 Class: Common Stock, par value $0.0001 per share

Composite Decision Signal · PASS (LOW BASE-RATE EDGE) Conviction Score: 37/100

Active Schedule 13D filer baseline
2 NPORT-P mutual funds holding CUSIP
Elevated short days-to-cover (5.3 DTC)
Short interest building (+21.0% vs prior settlement)

Item 4 — Purpose of Transaction

Not extracted from this filing — typically because it's an amendment (13D/A) and Item 4 is unchanged from the parent filing. Read the raw SEC filing →

Cross-References

Insider Activity (last 365d)

0 transactions

0 buys · 0 sales · 0 awards/exercises

Issuer Cluster

9 13D/G filings on this issuer

8 other filings besides this one

Filer Track Record

4 filings by this filer

3 other filings in the data moat

Short Interest · settle 2026-10-15

DTC 5.25

5,652,682 shares short · +21.0% vs prior

Post-Filing Returns · since 2026-05-26 on QTTB

+1 day

0.0%

+5 days

0.0%

+30 days

0.0%

+60 days

+11.7%

+90 days

—

+180 days

—

Anchor price 13.62 on closest trading day on/after 2026-05-26. Source: Yahoo Finance daily adj_close (split + dividend adjusted).

Other 13D/G Filings on Q32 Bio Inc.

Filed	Form	Filer	Stake	Shares
2026-10-09	SCHEDULE 13G	Frazier Life Sciences Public Fund, L.P.	—	—	view →
2026-07-20	SCHEDULE 13D/A	ORBIMED ADVISORS LLC	—	4,127,987	view →
2026-07-10	SCHEDULE 13G	Boxer Capital Management, LLC	—	—	view →
2026-06-04	SCHEDULE 13G	BIOTECHNOLOGY VALUE FUND L P	—	—	view →
2026-06-01	SCHEDULE 13D/A	ORBIMED ADVISORS LLC	—	4,127,987	view →
2020-04-20	SC	Flynn James E	—	—	view →
2020-01-31	SC	Flynn James E	—	—	view →
2019-12-30	SC	Flynn James E	—	—	view →

Other Filings by Atlas Venture Fund X, L.P.

Filed	Form	Issuer	Stake	Shares
2022-12-06	SC	Replimune Group, Inc. REPL	—	—	view →
2021-02-16	SC	Spero Therapeutics, Inc. SPRO	—	—	view →
2020-07-07	SC	Replimune Group, Inc. REPL	—	—	view →

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