The Import Price Index is a measure of inflation from the perspective of imports. A higher than expected index suggests rising costs of imported goods, which can contribute to overall inflation. This, in turn, may influence the Federal Reserve's monetary policy decisions, particularly regarding interest rates. Changes in interest rates can affect the stock market, and SPY, being a broad market ETF, is likely to reflect these macroeconomic shifts. However, the direct impact on SPY in the short term may be mixed, as market participants weigh the potential for economic growth against the risks of higher inflation and interest rates.