The U.S. stock market swung through another unsettled day of trading on Wednesday, ahead of a couple of crucial tests for Wall Street.

The S&P 500 rose 0.4% after veering between a small loss and a leap of 1.1% earlier in the day. That broke a four-day losing streak, the longest in nearly three months for the index, which has been shaking because of worries that stock prices have shot too high and that the Federal Reserve may not deliver as many cuts to interest rates as expected.

The Dow Jones Industrial Average added 47 points, or 0.1%, and the Nasdaq composite climbed 0.6%.

Constellation Energy led the market and rallied 5.3% after the U.S. Department of Energy said it’s lending $1 billion to help restart Constellation’s nuclear power plant at Three Mile Island. Lowe’s rose 4% after the home-improvement retailer reported a stronger profit for the summer than analysts expected.

They helped offset a 2.8% drop for Target, which reported weaker revenue for the latest quarter than analysts expected. The retailer also hinted that challenges may continue through the critical holiday shopping season.

The market’s focus, though, remained on Nvidia. Wall Street’s most influential stock climbed 2.8% as traders made their final moves ahead of the chip company’s profit report, scheduled to arrive after trading finished for the day.

So much is riding on it.

Nvidia has grown to become the largest stock on Wall Street and briefly topped $5 trillion in value. That means its movements have more of an effect on the S&P 500 than any other stock, and it can single-handedly steer the index’s direction some days.