Coinbase shares closed down more than 8% Monday, extending a slide that’s pushed the crypto exchange to its lowest point since its market debut in April 2021. The drop comes as bitcoin’s slump continues and investors worry about contagion from FTX’s spectacular collapse earlier this month.Nineteen months after going public with a market cap of over $85 billion, Coinbase has fallen below the $10 billion mark and has lost over a quarter of its value in the past four trading sessions.Questions have been swirling about the health of FTX’s rival exchanges, sparking industrywide sell-offs that have caused some companies to temporarily suspend trading, and others to prepare potential bankruptcy filings. Mizuho analysts wrote in a note on Friday that daily volumes in the industry are trending 30% to 40% below their average for the year.CNBC.com