Coinbase Global (COIN) slides 3.2% in premarket trading even as bitcoin recovers some of the ground it lost over the weekend.One reason may be insider sales of the stock in its first day of trading. Chairman and CEO Brian Armstrong sold 750K shares in the first day of trading for ~$292M, reducing his holdings in the company to 300,358 shares.Other Coinbase directors and officers who sold off part of their holdings on that first day were directors Frederick R. Wilson, Kathryn Haun, Frederick Ehrsam III, Chief Accounting Officer Jennifer Jones, Chief Financial Officer Alesia J. Haas, and President Emilie Choi.