Wall Street is sliding toward losses in premarket trading after Walmart, the nation’s biggest retailer and a bellwether for the health of the American consumer, gave a disappointing 2025 forecast.

However, the S&P 500 ( ^GSPC 0.24%) is generally considered the best barometer for the overall U.S. stock market due to its scope and diversity. Read on to see the S&P 500's average return over the last decade, and to learn what Wall Street expects in the future.

U.S. stock indexes are edging lower on a relatively quiet Wall Street. The S&P 500 slipped by 0.2%, a day after setting an all-time high.

U.S. stocks finished with losses Thursday, with the S&P 500 (SP500) pulling back from a record high, in part as investors balked at Walmart's (WMT) soft financial outlook. The outlook from the retail behemoth arrived at a time of uncertainty about the impact of tariffs on the U.