| Insider | Role | Shares | Value | Buys | Sells |
|---|---|---|---|---|---|
| Date | Ticker | Insider | Role | Type | Shares | Price | Value | Chg% | SEC |
|---|---|---|---|---|---|---|---|---|---|
| Insider | Role | Shares | Value | Buys | Sells |
|---|---|---|---|---|---|
| Date | Ticker | Insider | Role | Type | Shares | Price | Value | Chg% | SEC |
|---|---|---|---|---|---|---|---|---|---|
See Remarks | Former 10% Owner | 10% Owner +4 more
7 companies
Mark N. Tompkins is Former Director at GUER and has filed Form 4s across 7 companies. From June 2017 to May 2026, the filings on record show 6 open-market purchases and 28 sales. Mark N. Tompkins's net worth is not public. Form 4 filings only show shares in the companies where this person is an insider; those holdings are worth an estimated $44.8M at current prices.
Historically, Mark N. Tompkins's trades have earned a strong insider score of 86/100 across 74 rated trades. Over a 12-month horizon, all 56 of those trades were profitable, with an average 12-month return of +66.7%.
The biggest single holding is GUER (~$14.4M) as Former Director. Net of sales, the GUER filings show accumulation of 250,000 shares.
| Date | Ticker | Role | Type | Shares | Price | Value | Chg% | 3M | 12M | SEC |
|---|---|---|---|---|---|---|---|---|---|---|
| Mar 5, 2021 | AMST Amesite Inc. | 10% Owner | Sell | 20,000 | $5.62 | $112,455.52 | -0.7% | -61.0% | -89.6% | |
| Sep 29, 2020 | AMST Amesite Inc. | 10% Owner | Buy | 20,000 | $5.00 | $100,000.00 | +0.7% | - | - | |
| Sep 26, 2017 | XCUR Exicure, Inc. | Former Director and 10% Owner | Buy | 166,667 | $3.00 | $500,001.00 | +10.0% | - | - | |
| Jun 15, 2017 | XCUR Exicure, Inc. | Director, 10% Owner | Buy | 35,000 | $0.03 | $875.00 | +3.6% | - | - |