Insider · SEC Form 4 filer

Peter Kolchinsky

Past buys: 2 of 6 beat

Companies

Where they file as an insider

Artiva Biotherapeutics (ARTV) Director, 10% owner Latest filing Jul 23, 2026
Werewolf Therapeutics (HOWL) 10% owner Latest filing Jun 11, 2026
Hemab Therapeutics (COAG) 10% owner Latest filing May 12, 2026
Vor Biopharma (VOR) Director, 10% owner Latest filing Apr 6, 2026
Climb Bio (CLYM) Director, 10% owner Latest filing Dec 12, 2025
Sionna Therapeutics (SION) Director, 10% owner Latest filing Nov 21, 2025
Cidara Therapeutics (CDTX) Director, 10% owner Latest filing Jun 26, 2025
Tyra Biosciences (TYRA) Director, 10% owner Latest filing Jun 5, 2025

And 7 more companies with older filings.

Track record

Did their buys beat the typical stock?

Open-market buys20
Quarters checked 6 months later6
Beat the typical stock 2 of 6
Quarters too new to check2

2 of 6 checked quarters beat the typical stock. A past record is data, not a forecast.

Artiva Biotherapeutics (ARTV) Bought Jul 21–23, 2026 · $2.58M · 264,586 shares Too new Too new. Its 6-month check uses prices as of Mar 31, 2027.
Artiva Biotherapeutics (ARTV) Bought Jun 12–16, 2026 · $4.6M · 531,326 shares Too new Too new. Its 6-month check uses prices as of Dec 31, 2026.
Climb Bio (CLYM) Bought Dec 11–12, 2025 · $755K · 314,561 shares Not counted Not counted. We have no fund price for this stock on both Dec 31, 2025 and Jun 30, 2026.
Cidara Therapeutics (CDTX) Bought Jun 26, 2025 · $100M · 2.27M shares Not counted Not counted. We have no fund price for this stock on both Jun 30, 2025 and Dec 31, 2025.
Tyra Biosciences (TYRA) Bought Jun 4–5, 2025 · $11.8M · 1.21M shares Beat typical Jun 30, 2025 $9.57 → Dec 31, 2025 $26.29 · +174.7% (typical stock +2.1%)
89bio (ETNB) Bought Jan 30, 2025 · $50M · 5.71M shares Beat typical Mar 31, 2025 $7.27 → Sep 30, 2025 $14.70 · +102.2% (typical stock +7.3%)
Janux Therapeutics (JANX) Bought Oct 18, 2024 · $53.7M · 1.2M shares Behind typical Dec 31, 2024 $53.54 → Jun 30, 2025 $23.10 · −56.9% (typical stock −3.4%)
Artiva Biotherapeutics (ARTV) Bought Jul 22, 2024 · $100M · 8.33M shares Not counted Not counted. We have no fund price for this stock on both Sep 30, 2024 and Mar 31, 2025.
Eliem Therapeutics (ELYM) Bought Jun 27, 2024 · $50M · 13.01M shares Not counted Not counted. We have no fund price for this stock on both Jun 30, 2024 and Dec 31, 2024.
89bio (ETNB) Bought Mar 4, 2024 · $20.7M · 1.35M shares Behind typical Mar 31, 2024 $11.64 → Sep 30, 2024 $7.40 · −36.4% (typical stock +3.2%)
PepGen (PEPG) Bought Feb 9, 2024 · $27.2M · 2.56M shares Behind typical Mar 31, 2024 $14.70 → Sep 30, 2024 $8.55 · −41.8% (typical stock +3.2%)
Wave Life Sciences (WVE) Bought Dec 11, 2023 · $5M · 1M shares Behind typical Dec 31, 2023 $5.05 → Jun 30, 2024 $4.99 · −1.2% (typical stock −1.2%)

Each row is one stock in one quarter, however many buys it took. We take the stock's price at the end of that quarter and again 6 months later, and compare it with the typical stock over the same dates. Prices are quarter-end values from funds' 13F reports (the middle value across 3 or more funds), through Sep 30, 2026. Moves past 3 times up or down, mostly stock splits, are left out. How we tested this.

Past results. This is data, not advice.

Where this data comes from. Insider trades, fund holdings, activist stakes and company results come from public SEC EDGAR filings (Forms 4, 13F, 13D/13G, 10-Q and 8-K). Congress trades come from the STOCK Act reports members file with the House Clerk and the Senate. Daily closing prices come from post-no-preference/stocks on DoltHub, a community-run database shared under CC BY-SA 4.0; the prices we show stay under that license. They are each day's close, not live or official exchange prices.

This is data, not investment advice. About StockToast · Your watchlist