Arthur R. Baker III is CTO at Proto Labs Inc (PRLB). They have made 8 open-market trades across 2 companies since 2012, most recently 2022-02-17.
CIK 0001536324
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.
2 open-market purchases totalling $657K since 2016, against 6 sales. Too few scored purchases to measure a record yet.
| Ticker | Type | Traded | Filed | Price | Value | 7d Stock | 30d Stock | 90d Stock |
|---|---|---|---|---|---|---|---|---|
| PRLB | BUY | 2021-12-01 | 2021-12-01 | $49.21 | $492K | +5.8% | +4.7% | +11.8% |
| PRLB | SELL | 2021-02-16 | 2021-02-18 | $186.52 | $1.8M | -17.6% | -28.8% | -47.2% |
| PRLB | SELL | 2020-05-18 | 2020-05-20 | $115.07 | $458K | -0.6% | -11.4% | +5.9% |
| PRLB | SELL | 2018-09-04 | 2018-09-11 | $154.81 | $1.1M | +0.0% | -23.2% | -27.9% |
| PRLB | BUY | 2016-09-01 | 2016-09-06 | $55.00 | $165K | -2.2% | +4.8% | -5.1% |
| MTSC | SELL | 2014-02-13 | 2014-02-18 | $72.56 | $777K | -14.9% | -2.9% | -2.9% |
| MTSC | SELL | 2013-09-10 | 2013-09-12 | $59.99 | $202K | -14.9% | -2.9% | -2.9% |
| MTSC | SELL · 10b5-1 | 2012-10-01 | 2012-10-03 | $54.00 | $339K | -14.9% | -2.9% | -2.9% |
| MTSC | SELL | 2012-06-29 | 2012-07-03 | $10.00 | $1K | -14.9% | -2.9% | -2.9% |
Grouped by shared companies and similar filing behaviour. This is a similarity measure, not a ranking or a performance signal.