RTW INVESTMENTS, LP: ERASCA INC (ERAS): Quarterly 13F Position History
As of Q1 2026, RTW INVESTMENTS, LP reported 16,157,175 shares of ERASCA INC (ERAS), worth $261.4M and representing 2.6% of its 13F equity book. Quarter-over-quarter share count change: + 16,010,524 (+10917.4%) . The position first appeared in Q4 2025 and has been disclosed across 2 13F-HR filings in Pactolio's tracked window.
- 16,157,175Shares Held (Latest Filing)
- $261.4MReported Market Value (Latest Filing)
- 2.6%Portfolio Weight (% of 13F Equity Book)
- +16,010,524Quarter-over-Quarter Share Change
- +$260.9MQuarter-over-Quarter Value Change
- 16,157,175Peak Reported Shares (Historical)
Recent initiation: RTW INVESTMENTS, LP first reported ERAS on the Q4 2025 filing — fewer than three quarters of history are available.
Quarterly 13F-HR Disclosure History Source: SEC 13F-HR filings, 2 quarter s
| Quarter | Shares | QoQ Share Change | Share Change (%) | Market Value | Weight | Implied Price |
|---|---|---|---|---|---|---|
| Q1 2026 | 16,157,175 | +16,010,524 | +10917.4% | $261.4M | 2.6% | $16.2 |
| Q4 2025 | 146,651 | — | — | $545.5K | 0.0% | $3.7 |
Methodology & FAQ
How This Position History Is Sourced
Each row is one SEC Form 13F-HR filing disclosing this position. Share count, market value, and reported quarter are taken verbatim from the filing; portfolio weight is recomputed against the same filing's total reported equity book. Implied price-per-share is market value divided by shares — a quarter-end mark, not the manager's cost basis. See the full methodology document for the normalization rules.
When did RTW INVESTMENTS, LP first disclose a ERAS position in 13F-HR filings?
RTW INVESTMENTS, LP first reported ERASCA INC (ERAS) on its 13F-HR filing for the period ending 2025-12-31 (Q4 2025). The position has appeared on 2 reported quarters within Pactolio's tracked window.
What was RTW INVESTMENTS, LP's most recent quarter-over-quarter share-count change in ERAS?
Between Q4 2025 and Q1 2026, RTW INVESTMENTS, LP added 16,010,524 shares of ERAS (+10917.4%), bringing the total reported position to 16,157,175 shares at a market value of $261.4M.
Does the implied price-per-share represent RTW INVESTMENTS, LP's cost basis in ERAS?
No. The implied price-per-share column is the 13F-HR reported market value divided by reported share count on the filing date (end of quarter). It is a quarter-end mark, not a cost basis or transaction price. Use it as a sanity check on the value column, not as an indicator of the manager's entry or exit price.