David M. Demski sold Alphatec Holdings ($ATEC) shares once on the open market in the last year, totaling $636,000, with the most recent sale on December 11, 2025. This ranks him 5,966th among 11,678 insiders by sale value, below the average of $8.6 million across 6.37 transactions per insider. He made no open market purchases during this period.
| Transaction Date | Company | Ticker | Insider Name | Title | Transaction Type | Security | Shares | Price | Shares Owned Following | Total Shares Outstanding | % of Owned | % of Outstanding |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dec. 11, 2025 | Alphatec Holdings, Inc. | $ATEC | Demski David M | Not found | S | Common Stock | 30000 | $21.20 | 399,623.0000 | 151,401,000 | 6.98% | 0.02% |
| June 11, 2025 | Alphatec Holdings, Inc. | $ATEC | Demski David M | Not found | A | Common Stock | 15131 | $0.00 | 429,623.0000 | 142,946,000 | 3.65% | 0.01% |
| Dec. 18, 2024 | Alphatec Holdings, Inc. | $ATEC | Demski David M | Not found | A | Common Stock | 126051 | $0.00 | 414,492.0000 | 143,492,000 | 43.70% | 0.09% |
| Aug. 21, 2024 | Alphatec Holdings, Inc. | $ATEC | Demski David M | Not found | P | Common Stock | 50000 | $5.67 | 288,441.0000 | 121,242,000 | 20.97% | 0.04% |
| Aug. 2, 2024 | Alphatec Holdings, Inc. | $ATEC | Demski David M | Not found | P | Common Stock | 40000 | $6.56 | 238,441.0000 | 121,242,000 | 20.16% | 0.03% |
| June 12, 2024 | Alphatec Holdings, Inc. | $ATEC | Demski David M | Not found | A | Common Stock | 16747 | $0.00 | 198,441.0000 | 121,242,000 | 9.22% | 0.01% |
| Nov. 9, 2023 | Alphatec Holdings, Inc. | $ATEC | Demski David M | Not found | P | Common Stock | 30000 | $10.50 | 181,694.0000 | 103,373,000 | 19.78% | 0.03% |
| Oct. 17, 2023 | Alphatec Holdings, Inc. | $ATEC | Demski David M | Not found | A | Common Stock | 23852 | $0.00 | 151,694.0000 | 103,373,000 | 18.66% | 0.02% |
| Oct. 17, 2023 | Alphatec Holdings, Inc. | $ATEC | Demski David M | Not found | A | Common Stock | 7842 | $0.00 | 127,842.0000 | 103,373,000 | 6.54% | 0.01% |