Bryan Giraudo is COO & CFO at Gossamer Bio, Inc. (GOSS). They have made 16 open-market trades across 2 companies since 2017, most recently 2026-05-08.
CIK 0001740847
12 open-market purchases totalling $887K since 2017, against 4 sales. Across 12 scored buys the stock is up 18.3% at ninety days, and 13.1 points ahead of the S&P over the same stretch.
12 scored purchases · one row per filing · discretionary only
| Ticker | Shares | Value |
|---|---|---|
| GOSS | 389,737 | $3.4M |
| PTGX | 12,695 | $1.6M |
| Total | $5.0M |
Shares reported on the most recent Form 4, priced at the 2026-05-11 close.
Counted per filing, not per execution lot — a purchase filled in several tranches is one decision.
| 7d | 30d | 90d | |
|---|---|---|---|
| Accuracy | 58% | 83% | 83% |
| Avg Move | +10.0% | +21.6% | +18.3% |
| Alpha | +8.5% | +17.5% | +13.1% |
| Scored | 12 | 12 | 12 |
| Ticker | Type | Traded | Filed | Price | Value | 7d Stock | 30d Stock | 90d Stock |
|---|---|---|---|---|---|---|---|---|
| PTGX | SELL | 2026-05-07 | 2026-05-11 | $100.10 | $5.9M | +0.1% | +3.9% | +47.1% |
| GOSS | BUY | 2024-06-18 | 2024-06-20 | $0.59 | $59K | +60.0% | +76.7% | +51.8% |
| GOSS | SELL | 2024-03-27 | 2024-03-28 | $1.16 | $7K | -15.3% | -41.0% | -20.4% |
| GOSS | BUY | 2023-11-13 | 2023-11-14 | $0.56 | $224K | +8.4% | +49.5% | +27.7% |
| GOSS | BUY | 2023-04-04 | 2023-04-05 | $1.02 | $56K | -6.7% | +29.5% | +21.9% |
| GOSS | BUY | 2023-03-20 | 2023-03-22 | $0.97 | $49K | -12.5% | -5.5% | +2.7% |
| GOSS | BUY | 2022-07-15 | 2022-07-15 | $7.21 | $200K | +3.0% | +23.2% | +5.3% |
| GOSS | SELL | 2022-03-23 | 2022-03-24 | $8.92 | $191K | -1.6% | +2.1% | -18.2% |
| GOSS | SELL | 2021-03-23 | 2021-03-25 | $9.48 | $104K | -1.2% | -3.8% | -9.9% |
| GOSS | BUY | 2020-10-14 | 2020-10-14 | $10.01 | $30K | -3.9% | -6.5% | +8.0% |
| GOSS | BUY | 2020-06-23 | 2020-06-23 | $12.96 | $26K | +1.4% | +8.4% | -2.6% |
| PTGX | BUY | 2019-12-03 | 2019-12-03 | $5.70 | $46K | +33.2% | +26.0% | +44.0% |
| GOSS | BUY | 2019-09-26 | 2019-09-26 | $16.78 | $19K | -6.4% | +18.2% | -0.8% |
| GOSS | BUY | 2019-05-30 | 2019-06-03 | $18.70 | $19K | -0.2% | +13.0% | +11.4% |
| GOSS | BUY | 2019-02-12 | 2019-02-12 | $16.00 | $96K | +25.2% | +8.1% | +9.4% |
| PTGX | BUY | 2017-05-16 | 2018-05-17 | $6.46 | $65K | +18.4% | +19.0% | +40.9% |
Grouped by shared companies and similar filing behaviour. This is a similarity measure, not a ranking or a performance signal.