Stocks are falling as Wall Street’s worries about the U.S. banking system crank even higher. The S&P 500 was 0.5% lower Thursday as several market-moving forces swirled, from the latest rate increase by the European Central Bank to a report indicating more U.S. workers got laid off last week than expected. The Dow was down nearly 300 points. PacWest Bancorp's stock nearly halved as investors look for the next weak link following several big U.S. bank failures. Other smaller and mid-sized banks were also falling sharply. Helping to limit the market's losses were several companies reporting better profits than expected.