Starboard Principal Co LP
CIK 1517139 · last filed 2025-05-16
Starboard Principal Co LP is a corporate insider who has filed 9 SEC Form 4 insider transactions across 7 companies since 2012. The most recent filing, for ACTG, was dated May 16, 2025. Across all open-market trades the lifetime net is +$43.4M, making them a net buyer over the disclosed history. Current disclosed insider exposure totals $40.7M across reported positions. The firm reports its address in New York, NY. 49 SEC filings were submitted jointly with Starboard Principal Co GP LLC.
"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.
Charts
Trading activity, where the exposure sits, and each trade against the stock price.
ODP price and trades
Daily close with each Form 4 filing on this company marked: green = open-market buy, red = open-market sale, purple = grants, exercises, gifts and other non-market transactions. Marker size scales with the dollar value.
Shares held
Shares owned after each reported transaction on this company (direct holdings as reported).
Open-market buying and selling
by monthDollar value of open-market purchases (code P, up) and sales (code S, down) across all companies, by filing month. Grants, exercises and gifts are excluded.
Exposure by company
latestMost recently reported shares × current price. Faded bars (*) have had no filing in 3 years, so the person may no longer hold them. Click a bar to chart that company.
Filer Profile
NEW YORK, NY 10017
Holdings By Company
| Symbol | Role | Shares | Price | Disclosed Exposure | Lifetime OM Net | Filings | Latest Filed |
|---|---|---|---|---|---|---|---|
| ACTG | 10%+ Owner | 0 | $4.17 | $0 | $0 | 2 | 2025-05-16 |
| GDOT | 853,129 | $12.11 | $10.33M | -$6.89M | 1 | 2024-03-08 | |
| Mellanox Technologies, Ltd. (MLNX) Delisted | 10%+ Owner | 3,758,713 | — | — | $0 | 1 | 2018-03-02 |
| QUANTUM CORP /DE/ (QTM) Delisted | 10%+ Owner | 534,662 | — | — | -$61.30M | 2 | 2016-12-07 |
| WPP | 10%+ Owner | 1,140,650 | $26.66 | $30.41M | $5.61M | 1 | 2012-11-02 |
| ODP Corp (ODP) Delisted | 10%+ Owner | 1,211,793 | $28.00 | $33.93M | $142.53M | 1 | 2012-09-17 |
| SURMODICS INC (SRDX) Delisted | 10%+ Owner | 1,406,667 | $42.98 | $60.46M | -$36.55M | 1 | 2012-08-10 |
Recent Filings
9 filings| Filed | Symbol | Action | Net Shares | Net $ | Link |
|---|---|---|---|---|---|
| 2025-05-16 | ACTG | Other (J) | — | $0 | EDGAR |
| 2024-03-08 | GDOT | Sell (S) | −827,187 | -$6.89M | EDGAR |
| 2023-07-17 | ACTG | Exer (M) | +164,494,380 | $600.40M | EDGAR |
| 2018-03-02 | Mellanox Technologies, Ltd. (MLNX) Delisted | Exer (X) | +4,600,000 | $115.00M | EDGAR |
| 2016-12-07 | QUANTUM CORP /DE/ (QTM) Delisted | Sell (S) | −70,650,000 | -$64.38M | EDGAR |
| 2013-04-08 | QUANTUM CORP /DE/ (QTM) Delisted | Buy (P) | +2,500,000 | $3.08M | EDGAR |
| 2012-11-02 | WPP | Buy (P) | +675,000 | $5.61M | EDGAR |
| 2012-09-17 | ODP Corp (ODP) Delisted | Buy (P) | +62,252,829 | $142.53M | EDGAR |
| 2012-08-10 | SURMODICS INC (SRDX) Delisted | Sell (S) | −2,060,480 | -$36.55M | EDGAR |
Notice (144 / 144/A): Form 144 is a notice of intent to sell restricted/control stock under Rule 144, filed before the sale; 144/A is an amendment. Many notices are pre-scheduled under Rule 10b5-1 plans. A Form 4 with code S typically follows within a few days when the planned sale executes; missing follow-up Form 4s suggest the notice was cancelled or modified.