FULC — blockholders· FULCRUM THERAPEUTICS, INC.
Everyone who has reported crossing 5% of this issuer inside the capture window — Schedule 13D (active intent, with its Item-4 purpose) and Schedule 13G (passive by rule) kept apart — each with its full amendment chain and, in the fold, the cover page's sole and shared voting and dispositive power per reporting person. Percents are each group's own as-filed figures and do not add up across filers: two filers can report the same shares.
Filed passively under Rule 13d-1(b) (qualified institution), (c) (passive investor) or (d) (exempt). A 13G filer is not an activist and files no purpose statement.
| Filer | Form | % of class | Change | Shares | Filed | Chain | Control | Filing |
|---|---|---|---|---|---|---|---|---|
| TANG CAPITAL MANAGEMENT, LLC | 13G/A No. 1Passive | 10.4% | ▲ +2.2pp | 6,913,329 | 2026-07-15 | 2 | SEC ↗ | |
| EcoR1 Capital, LLC | 13GQII | 9% | no change | 6,000,000 | 2026-06-25 | 2 | SEC ↗ | |
| Nantahala Capital Management, LLC | 13GQII | 8.22% | ▲ +3.64pp | 5,475,040 | 2026-08-14 | 3 | SEC ↗ | |
| BlackRock, Inc. | 13G/A No. 4QII | 7.2% | ▲ +1.2pp | 4,802,880 | 2026-07-28 | 3 | SEC ↗ | |
| BANK OF AMERICA CORP /DE/ | 13GQII | 6.7% | NEW | 4,468,123 | 2026-08-03 | 1 | SEC ↗ | |
| BlackRock Portfolio Management LLC | 13GQII | 6% | NEW | 4,021,379 | 2026-07-17 | 1 | SEC ↗ | |
| Montanova Capital, LLC | 13G/A No. 2QII | 5.5% | ▼ -3.9pp | 3,680,921 | 2026-08-14 | 3 | SEC ↗ | |
| Adage Capital Management, L.P. | 13G/A No. 2QII | 4.5% | ▼ -4pp | 2,432,000 | 2025-11-13 | 3 | SEC ↗ | |
| RA Capital Management, L.P. | 13G/A No. 7Passive | 0% | EXITED | 0 | 2026-08-14 | 3 | SEC ↗ | |
| The Vanguard Group | 13G/A No. 2QII | 0% | first captured | 0 | 2026-03-26 | 1 | SEC ↗ |
Source: SEC EDGAR Schedule 13D/G structured XML (public domain) · newest filing 2026-08-14 · capture 2024-01-10 → 2026-08-21 reported positions only — not a portfolio
Voting is not disposition. Each reporting person's cover page splits its holding into VOTING power (sole / shared) and DISPOSITIVE power (sole / shared). Voting and dispositive totals are summed WITHIN a person only — never across persons, because a group's members report overlapping interests in the same shares and the filing's aggregate is not their sum. Where a person's voting total is below its reported aggregate, the difference is shares it reports beneficial ownership of with no voting power reported; it is shown as a gap, never as a second position.
Percent is as filed. Percent is the filing's own percent of class, as filed (0–100). It's the reporting group's figure — not summed across filers, not recomputed against shares outstanding, not rescaled. Share counts are as filed and never subtracted across filings (a split would make that meaningless); the only change we show is the change in the as-filed percent against the prior captured filing.
We never call an amendment “new”. A filing is 'first captured' when we hold nothing earlier for that company + filer. On an amendment that means the original predates our window, not that the position is new — so we never badge an amendment 'new,' even when the raw data says so.
Escalations. An escalation is a filer moving from a passive 13G to an active 13D on the same company — telling the SEC it may now seek to influence control. It's a lower bound: a 13G filed before our window began is invisible and never guessed. If the 13D leg is a 13D/A, an earlier 13D predates our window, so the crossing shown is the first one visible inside it, not necessarily the filer's first.
Parsed Schedule 13D/G XML (events.db schedule_13dg + schedule_13dg_persons). 13D = active intent; 13G filers report passively under Rule 13d-1(b) QII / (c) Passive / (d) Exempt and are never activists. Percents are the reporting group's own as-filed figures and are NOT additive across filers — two filers can report the same shares. Structured 13D/13G coverage starts December 2024 (SEC XML mandate).