The Securities and Exchange Commission has told Coinbase Global that it plans to take enforcement action against the company, escalating its crackdown on digital-currency firms by targeting the biggest US crypto exchange, Coinbase said on 22 March.

Coinbase said it had received a letter from the SEC known as a Wells notice, in which regulators say they believe companies or individuals violated investor-protection laws. The notices aren’t final because the agency’s commissioners must authorize any lawsuits or enforcement settlements.