David M Demski
At a glance: David M Demski is Director at Alphatec Holdings (ATEC). Their latest SEC Form 4, filed Nov 2, 2026, reported a purchase of $409K. On file: 1 purchase line ($409K) and 1 sale line ($636K).
Director at Alphatec Holdings, Inc. (ATEC)
Purchase track record
Not enough history. Based on 0 purchases with a full 90 days of price history.
Every purchase since 2023
From the SEC's insider data sets: each open-market buy by David M Demski, matched to how the stock did over the next 90 days against the S&P 500.
3 of 3 buys beat the S&P 500 (100%), median +54.5% vs. the index. Small sample: treat with care. All insider buys: 46%.
Buys made close together in one stock count once. Price-only returns; history, not a prediction.
Reported trades
| Filed | Stock | Type | Shares | Price | Value | Since |
|---|---|---|---|---|---|---|
| Nov 2SEC | ATECAlphatec Holdings, Inc. | Buy | 60,000491,635 held (+14%) | $6.81 | $409K | +8.4% |
| Dec 12SEC | ATECAlphatec Holdings, Inc. | Sell | 30,000399,623 held (−7%) | $21.20 | $636K | -65.2% |
- Buy
Director David M Demski bought $409K of ATEC at $6.81 — first open-market purchase in our records.