Movus/iStock Editorial via Getty Images Raymond James analyst Patrick O'Shaughnessy initiates coverage of Coinbase Global (COIN) at Underperform as he expects the cryptocurrency exchange to suffer from pricing degradation over time. While the company is well-positioned as a market leader in the fast-growing crypto trading market, "we don't see a structural barrier to entry here," he writes in a note to clients. "Over and over again history has shown that brokerages and exchanges see excess profits competed away unless there is a structural barrier to entry," O'Shaughnessy said. Coinbase stock ends the session down 4.7% on a day when crypto prices were also sliding. Shares are falling 0.6% in after-hours trading. The Underperform rating clashes with the average Wall Street rating of Bullish (6 Very Bullish, 3 Bullish, 4 Neutral). Bitcoin is down 4.4% to $32.9K and ethereum drops 5.4% to ~$2,517. Earlier today, the head of the IRS asked Congress for the authority to get data