March 22 (Reuters) - The U.S. Securities and Exchange Commission (SEC) has threatened to sue Coinbase Global Inc (COIN.O) over some of the crypto exchange's products, turning up the heat on the largely unregulated sector. Shares of Coinbase dropped nearly 13% to $67.33 in extended trading after the company said on Wednesday that the regulator had issued it a Wells notice - a formal declaration that SEC staff intend to recommend an enforcement action. The potential enforcement actions would be tied to aspects of Coinbase's spot market as well as its Earn, Prime and Wallet products, the company said. The...