SEC Filings - https://investor.coinbase.com/financials/sec-filings/default.... Look out for "Statement of Changes in Beneficial Ownership" to see stock grants/ sales for insiders (executives and directors).

But, scouring SEC filings can be demanding, so there are several websites that specialize in extracting and displaying such information, for example - https://www.marketbeat.com/stocks/NASDAQ/COIN/insider-trades...