美国4月S&P/CS20座大城市季调后房价指数环比 -0.31%，预期 0%，前值 -0.12%。

Group 1 - The core point of the article indicates that the S&P/CS 20-City Composite Home Price Index in the U.S. decreased by 0.31% month-over-month in April, contrasting with the expected 0% change and a previous value of -0.12% [1]