Shuo Zhang is Director at GRID DYNAMICS HOLDINGS, INC. (GDYN). They have made 10 open-market trades across 2 companies since 2020, most recently 2026-08-12.
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.
1 open-market purchase totalling $158K since 2020, against 9 sales. Too few scored purchases to measure a record yet.
| Ticker | Shares | Value |
|---|---|---|
| PDFS | 23,380 | $916K |
| GDYN | 104,772 | $817K |
| Total | $1.7M |
Shares reported on the most recent Form 4, priced at the 2026-08-12 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 |
|---|---|---|---|---|---|---|---|---|
| PDFS | SELL | 2026-08-12 | 2026-08-12 | $51.47 | $77K | -14.8% | -7.7% | — |
| GDYN | SELL | 2025-12-15 | 2025-12-17 | $9.75 | $29K | -4.3% | -4.4% | -35.1% |
| PDFS | SELL | 2024-06-03 | 2024-06-04 | $34.66 | $381K | -3.9% | +3.9% | -16.5% |
| GDYN | SELL | 2024-06-03 | 2024-06-05 | $9.34 | $37K | +2.8% | +11.8% | +43.6% |
| PDFS | SELL | 2023-08-18 | 2023-08-21 | $33.75 | $206K | +5.3% | -8.0% | -9.9% |
| PDFS | SELL | 2022-11-16 | 2022-11-17 | $29.84 | $60K | +1.4% | -4.6% | +8.7% |
| PDFS | SELL | 2022-03-15 | 2022-03-17 | $25.50 | $562K | +6.8% | -13.4% | -23.8% |
| GDYN | SELL | 2021-11-29 | 2021-12-01 | $39.38 | $276K | -0.2% | +1.8% | -71.6% |
| GDYN | SELL | 2021-09-08 | 2021-09-09 | $31.63 | $316K | +0.9% | -6.3% | +32.5% |
| GDYN | BUY | 2020-08-12 | 2020-08-18 | $7.61 | $158K | +2.5% | -0.9% | +14.1% |
Grouped by shared companies and similar filing behaviour. This is a similarity measure, not a ranking or a performance signal.