Donald G. Krantz is Director at Proto Labs Inc (PRLB). They have made 1 open-market trade across 1 company since 2012, most recently 2026-05-19.
CIK 0001183159
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 1 sale. Too few scored purchases to measure a record yet.
| Ticker | Shares | Value |
|---|---|---|
| PRLB | 26,863 | $2.3M |
Shares reported on the most recent Form 4, priced at the 2026-05-21 close.
| Ticker | Type | Traded | Filed | Price | Value | 7d Stock | 30d Stock | 90d Stock |
|---|---|---|---|---|---|---|---|---|
| PRLB | SELL | 2016-03-14 | 2016-03-16 | $75.11 | $3.9M | +5.7% | +6.1% | -16.9% |
| PRLB | SELL · 10b5-1 | 2015-07-24 | 2015-07-28 | $78.01 | $4.0M | -10.5% | +0.5% | +0.5% |
| PRLB | SELL · 10b5-1 | 2015-04-16 | 2015-04-20 | $79.00 | $94K | -10.5% | +0.5% | +0.5% |
| PRLB | SELL · 10b5-1 | 2013-04-10 | 2013-04-12 | $50.56 | $2.1M | -10.5% | +0.5% | +0.5% |
| PRLB | SELL · 10b5-1 | 2013-03-15 | 2013-03-19 | $46.86 | $2.2M | -10.5% | +0.5% | +0.5% |
| PRLB | SELL · 10b5-1 | 2013-02-01 | 2013-02-05 | $41.03 | $410K | -10.5% | +0.5% | +0.5% |
| PRLB | SELL · 10b5-1 | 2013-01-02 | 2013-01-04 | $39.65 | $595K | -10.5% | +0.5% | +0.5% |
| PRLB | SELL · 10b5-1 | 2012-12-19 | 2012-12-21 | $38.07 | $381K | -10.5% | +0.5% | +0.5% |
| PRLB | SELL · 10b5-1 | 2012-12-03 | 2012-12-05 | $36.45 | $182K | -10.5% | +0.5% | +0.5% |
| PRLB | SELL · 10b5-1 | 2012-11-26 | 2012-11-27 | $35.06 | $87K | -10.5% | +0.5% | +0.5% |
| PRLB | SELL · 10b5-1 | 2012-11-01 | 2012-11-05 | $35.01 | $88K | -10.5% | +0.5% | +0.5% |
| PRLB | SELL · 10b5-1 | 2012-10-25 | 2012-10-29 | $35.37 | $177K | -10.5% | +0.5% | +0.5% |
Grouped by shared companies and similar filing behaviour. This is a similarity measure, not a ranking or a performance signal.