Mark Campbell Winmill is CEO & President at Global Self Storage, Inc. (SELF). They have made 34 open-market trades across 4 companies since 2006, most recently 2026-09-10.
CIK 0001019264
31 open-market purchases totalling $671K since 2006, against 3 sales. Across 23 scored buys the stock is up 1.6% at ninety days, and 3.5 points behind the S&P over the same stretch.
24 scored purchases · one row per filing · discretionary only
| Ticker | Shares | Value |
|---|---|---|
| SELF | 372,582 | $1.8M |
| BXL | 20 | — |
| GIFD | 20,241 | — |
| TUX | 16,614 | — |
| Total | $1.8M |
Shares reported on the most recent Form 4, priced at the 2026-09-11 close. 3 holdings could not be priced and are excluded from the total.
| 7d | 30d | 90d | |
|---|---|---|---|
| Accuracy | 50% | 33% | 57% |
| Avg Move | +0.4% | +0.4% | +1.6% |
| Alpha | -1.2% | +0.3% | -3.5% |
| Scored | 24 | 24 | 23 |
| Ticker | Type | Traded | Filed | Price | Value | 7d Stock | 30d Stock | 90d Stock |
|---|---|---|---|---|---|---|---|---|
| SELF | BUY | 2026-09-09 | 2026-09-11 | $5.16 | $21K | -2.9% | -3.3% | — |
| SELF | BUY | 2026-05-14 | 2026-05-15 | $5.33 | $21K | -8.6% | -7.8% | -7.5% |
| SELF | BUY | 2025-12-03 | 2025-12-05 | $5.12 | $84K | +0.0% | +1.0% | +2.0% |
| SELF | BUY | 2025-05-19 | 2025-05-20 | $5.67 | $57K | -0.7% | -3.2% | -10.9% |
| SELF | BUY | 2024-05-28 | 2024-05-30 | $4.96 | $114K | -3.2% | -5.2% | +4.2% |
| SELF | BUY | 2023-11-16 | 2023-11-17 | $4.83 | $35K | -2.8% | -2.1% | -8.9% |
| SELF | BUY | 2023-08-17 | 2023-08-18 | $5.07 | $5K | -1.8% | -1.2% | -5.5% |
| SELF | BUY | 2023-05-15 | 2023-05-16 | $5.13 | $32K | -2.5% | -1.9% | -2.9% |
| SELF | BUY | 2022-11-18 | 2022-11-21 | $5.17 | $11K | -3.4% | -5.9% | +3.1% |
| SELF | BUY | 2022-08-23 | 2022-08-24 | $6.07 | $12K | -6.4% | -9.9% | -14.7% |
| SELF | BUY | 2022-05-20 | 2022-05-23 | $5.74 | $10K | +9.6% | +16.0% | +8.2% |
| SELF | BUY | 2021-08-24 | 2021-08-25 | $5.12 | $5K | +3.3% | -0.8% | +1.9% |
| SELF | BUY | 2021-08-20 | 2021-08-24 | $5.10 | $5K | +6.0% | -0.4% | +5.1% |
| SELF | BUY | 2020-11-19 | 2020-11-23 | $4.00 | $28K | +0.5% | +0.0% | +9.4% |
| SELF | BUY | 2020-08-19 | 2020-08-21 | $3.91 | $27K | +2.2% | +2.8% | +1.5% |
| SELF | BUY | 2020-05-20 | 2020-05-21 | $3.73 | $13K | +7.8% | +5.9% | +5.7% |
| SELF | BUY | 2019-05-28 | 2019-05-29 | $3.70 | $4K | +8.1% | +1.9% | +22.9% |
| SELF | BUY | 2018-05-18 | 2018-05-21 | $4.18 | $6K | +0.2% | -2.4% | -2.7% |
| SELF | BUY | 2017-08-23 | 2017-08-24 | $4.89 | $15K | -2.0% | -1.6% | +0.0% |
| SELF | BUY | 2016-11-30 | 2016-12-01 | $5.00 | $5K | -4.3% | -5.8% | -1.7% |
| SELF | BUY | 2016-08-23 | 2016-08-26 | $5.50 | $11K | +2.5% | -2.4% | -7.3% |
| SELF | BUY | 2016-05-26 | 2016-05-27 | $4.83 | $918 | +1.1% | +9.0% | +9.6% |
| SELF | BUY | 2016-05-25 | 2016-05-26 | $4.77 | $954 | +3.7% | +12.1% | +13.0% |
| SELF | BUY | 2016-05-23 | 2016-05-25 | $4.70 | $32K | +2.9% | +14.3% | +12.5% |
| GIFD | BUY | 2012-03-26 | 2012-03-28 | $4.07 | $41K | N/A | N/A | N/A |
Grouped by shared companies and similar filing behaviour. This is a similarity measure, not a ranking or a performance signal.
Counted per filing, not per execution lot — a purchase filled in several tranches is one decision.