Marcia Belvin is CSO & VP at CytomX Therapeutics, Inc. (CTMX). They have made 7 open-market trades across 1 company since 2023, most recently 2026-03-17.
CIK 0001970752
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 7 sales. Too few scored purchases to measure a record yet.
| Ticker | Shares | Value |
|---|---|---|
| CTMX | 300,760 | $707K |
Shares reported on the most recent Form 4, priced at the 2026-03-19 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 |
|---|---|---|---|---|---|---|---|---|
| CTMX | SELL | 2026-03-17 | 2026-03-19 | $6.42 | $404K | +1.7% | +6.0% | -36.0% |
| CTMX | SELL | 2025-06-16 | 2025-06-17 | $2.69 | $37K | -5.0% | -0.4% | -16.7% |
| CTMX | SELL | 2025-03-18 | 2025-03-20 | $0.60 | $12K | -10.1% | +16.3% | +227.1% |
| CTMX | SELL | 2024-08-20 | 2024-08-22 | $1.23 | $5K | +5.0% | -3.4% | -26.9% |
| CTMX | SELL | 2024-03-19 | 2024-03-21 | $2.09 | $27K | -2.7% | -24.4% | -42.1% |
| CTMX | SELL | 2023-12-20 | 2023-12-22 | $1.38 | $6K | +3.4% | +11.6% | +53.4% |
| CTMX | SELL | 2023-09-22 | 2023-09-22 | $1.30 | $5K | -3.2% | +1.6% | +11.9% |
Grouped by shared companies and similar filing behaviour. This is a similarity measure, not a ranking or a performance signal.