Arnon Rosenthal is CEO at Alector, Inc. (ALEC). They have made 21 open-market trades across 1 company since 2021, most recently 2026-10-14.
CIK 0001757770
Unrated. We grade insiders only on stock they chose to buy on the open market. Grants, option exercises and vesting say nothing about timing, so they don't count — which is why someone can file often and still have no grade. It isn't a bad sign: unrated buys beat every graded tier below A.
0 open-market purchases, against 21 sales. Too few scored purchases to measure a record yet.
| Ticker | Shares | Value |
|---|---|---|
| ALEC | 2,512,100 | $4.6M |
Shares reported on the most recent Form 4, priced at the 2026-10-15 close.
Counted per filing, not per execution lot — a purchase filled in several tranches is one decision.
| Ticker | Type | Traded | Filed | Price | Value | 7d Stock | 30d Stock | 90d Stock |
|---|---|---|---|---|---|---|---|---|
| ALEC | SELL | 2026-09-03 | 2026-09-04 | $2.66 | $193K | -21.2% | -15.8% | — |
| ALEC | SELL | 2026-06-02 | 2026-06-03 | $1.97 | $172K | -20.0% | +4.3% | +29.5% |
| ALEC | SELL | 2026-03-02 | 2026-03-03 | $2.12 | $174K | -0.5% | +9.0% | -6.3% |
| ALEC | SELL | 2025-12-03 | 2025-12-03 | $1.12 | $234K | +26.8% | +36.6% | +88.4% |
| ALEC | SELL | 2025-09-02 | 2025-09-04 | $2.50 | $129K | -2.5% | +12.4% | -59.7% |
| ALEC | SELL | 2025-06-02 | 2025-06-04 | $1.34 | $140K | -2.6% | -7.1% | +67.1% |
| ALEC | SELL | 2025-03-03 | 2025-03-05 | $1.47 | $119K | -8.6% | -32.5% | -2.0% |
| ALEC | SELL | 2024-12-02 | 2024-12-03 | $2.52 | $263K | -16.2% | -19.6% | -40.0% |
| ALEC | SELL | 2024-09-03 | 2024-09-04 | $4.88 | $259K | +22.9% | +0.0% | -45.5% |
| ALEC | SELL | 2024-06-03 | 2024-06-04 | $4.80 | $121K | -1.9% | -8.0% | -1.0% |
| ALEC | SELL | 2024-03-04 | 2024-03-05 | $6.92 | $261K | -10.9% | -16.2% | -26.8% |
| ALEC | SELL | 2023-12-04 | 2023-12-06 | $5.56 | $265K | +44.9% | +33.0% | +19.6% |
| ALEC | SELL | 2023-09-05 | 2023-09-06 | $5.19 | $29K | +18.1% | +28.7% | +5.8% |
| ALEC | SELL | 2023-06-02 | 2023-06-05 | $6.90 | $36K | +7.8% | -13.3% | -26.5% |
| ALEC | SELL | 2023-03-17 | 2023-03-21 | $6.22 | $189K | +1.3% | +7.5% | +19.5% |
| ALEC | SELL | 2023-03-02 | 2023-03-03 | $8.32 | $49K | -18.4% | -21.3% | -13.5% |
| ALEC | SELL | 2021-11-10 | 2021-11-12 | $25.00 | $2.8M | -9.1% | -8.1% | -28.8% |
| ALEC | SELL | 2021-11-08 | 2021-11-10 | $25.00 | $3.5M | -17.4% | -13.7% | -34.7% |
| ALEC | SELL | 2021-11-04 | 2021-11-08 | $25.00 | $3.5M | -8.2% | -4.5% | -32.0% |
| ALEC | SELL | 2021-09-22 | 2021-09-23 | $25.31 | $5.5M | -0.6% | -3.7% | -3.7% |
| ALEC | SELL | 2021-09-20 | 2021-09-22 | $25.96 | $10.4M | -9.0% | -6.1% | -7.4% |
Grouped by shared companies and similar filing behaviour. This is a similarity measure, not a ranking or a performance signal.