Mark Thierer
CIK 1334925 · Interim Chief Exec Officer · last filed 2026-01-23
Mark Thierer is an Interim Chief Exec Officer who has filed 53 SEC Form 4 insider transactions across 7 companies since 2008. The most recent filing, for PIIIW, was dated Jan 23, 2026. Across all open-market trades the lifetime net is −$70.0M, making them a net seller over the disclosed history. Current disclosed insider exposure totals $1.0M across reported positions.
"Disclosed insider exposure" sums this person's most-recently-reported share counts across each company they're an insider in, multiplied by the current underlying price. It is not net worth — it misses retail holdings, private investments, real estate, index funds, and any company where the person isn't an SEC-reporting insider. For informational purposes only.
$1.04M
7
53
-$70.02M
Holdings By Company
| Symbol | Role | Shares | Price | Disclosed Exposure | Lifetime OM Net | Filings | Latest Filed |
|---|---|---|---|---|---|---|---|
| PIIIW | Director | 21,182 | $0.02 | $356 | $0 | 5 | 2026-01-23 |
| Discover Financial Services (DFS) Delisted | Director | 24,563 | $200.05 | $4.91M | $0 | 6 | 2023-05-15 |
| XERS | Director | — | $6.79 | — | $0 | 2 | 2020-06-04 |
| XRAY | Interim Chief Exec Officer | 103,198 | $10.09 | $1.04M | $5.08M | 5 | 2018-02-27 |
| Discover Financial Services (DFSpB) Delisted | Director | 12,135 | — | — | $0 | 4 | 2017-05-12 |
| Catamaran Corp (CTRX) Delisted | President & CEO | 0 | — | — | -$23.68M | 12 | 2015-07-23 |
| Catamaran Corp (SXCI) Delisted | President & CEO | 95,408 | — | — | -$51.43M | 19 | 2012-06-06 |
Recent Filings
53 filings| Filed | Symbol | Action | Net Shares | Net $ | Link |
|---|---|---|---|---|---|
| 2026-01-23 | PIIIW | Grant (A) | +4,000 | $0 | EDGAR |
| 2025-08-08 | PIIIW | Grant (A) | +4,000 | $0 | EDGAR |
| 2024-06-10 | PIIIW | Grant (A) | — | $0 | EDGAR |
| 2024-01-25 | PIIIW | Grant (A) | +433,121 | $0 | EDGAR |
| 2023-05-15 | Discover Financial Services (DFS) Delisted | Grant (A) | +1,774 | $0 | EDGAR |
| 2022-05-23 | Discover Financial Services (DFS) Delisted | Grant (A) | +1,634 | $0 | EDGAR |
| 2022-03-28 | PIIIW | Grant (A) | — | $0 | EDGAR |
| 2021-05-06 | Discover Financial Services (DFS) Delisted | Grant (A) | +1,291 | $0 | EDGAR |
| 2020-06-04 | XERS | Grant (A) | — | $0 | EDGAR |
| 2020-05-18 | Discover Financial Services (DFS) Delisted | Grant (A) | +3,824 | $0 | EDGAR |