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Plaumann Mark Lawrence
Director
Mark Plaumann, age 70, has served as one of our directors since June 2025. Mr. Plaumann is currently a Managing Member of Greyhawke Capital Advisors LLC, or Greyhawke, which he co-founded in 1998. Prior to founding Greyhawke, Mr. Plaumann was a Senior Vice President of Wexford Capital LP. Mr. Plaumann was formerly a Managing Director of Alvarez & Marsal, Inc. and the President of American Healthcare Management, Inc. He also was Senior Manager at Ernst & Young LLP. Mr. Plaumann served as a director and audit committee chairman for ICx Technologies, Inc. from 2006 until 2010, served as a director and a member of the audit and compensation committees of Republic Airways Holdings, Inc. from 2002 until 2017 and…
Biography from the company’s latest DEF 14A proxy statement
Diamondback Energy, Inc. 7 open-market prints by this insider, 9/14/2015 – 8/21/2026. Triangles mark only their Form 4 purchases and sales. Full FANG chart
FANG trades
| Date | Form 4 | Ticker | Position | Side | Shares | Value | 90d | 180d |
|---|---|---|---|---|---|---|---|---|
| 8/21/2026 | Form 4 | FANG | Director | SELL | 1,000 | $210.6K | +3.66%hist | +7.30%hist |
| 6/9/2026 | Form 4 | FANG | Director | SELL | 500 | $98.3K | −3.35% | +7.30%hist |
| 11/13/2024 | Form 4 | FANG | Director | SELL | 1,150 | $208.2K | +10.7% | +20.6% |
| 11/13/2024 | Form 4 | FANG | Director | SELL | 240 | $43.4K | +10.7% | +20.6% |
| 5/23/2017 | Form 4 | FANG | Director | SELL | 1,000 | $101.5K | +13.5% | −7.27% |
| 2/17/2017 | Form 4 | FANG | Director | SELL | 1,900 | $204.0K | +5.58% | +18.2% |
| 9/14/2015 | Form 4 | FANG | Director | SELL | 3,000 | $197.0K | −15.0% | −15.7% |
Chart uses split-adjusted closes from the first print through the latest available bar. Returns use the last close on or before the trade date and the first close on or after 90 and 180 calendar days. Sales are signed so a declining price is a positive result for the seller. Not investment advice.