Should US regulators ban short-selling of bank stocks? That’s a hot topic as investors refuse to accept reassurance from the Fed chairman Jerome Powell that the recent banking crisis-that-wasn’t is over. Following JPMorgan’s rescue of First Republic, shares in other regional banks such as PacWest in Los Angeles, Western Alliance (Phoenix) and First Horizon (Memphis) have fluctuated wildly and fingers have pointed at short-sellers – who borrow shares they think are about to fall in order to sell, buy back cheaper and pocket a profit.