Stocks are mixed after the Federal Reserve announced its latest hike to interest rates, while also saying it may not tighten the screws much more on the economy. The S&P 500 was 0.2% higher Wednesday, while Treasury yields fell sharply. The Fed raised its key overnight rate by a quarter of a percentage point, the same size as its last increase, in its campaign to drive down inflation. It also said it may raise rates only one more time as it assesses the fallout from the crisis hitting the banking industry. Banks have been struggling under the weight of much higher rates.