The U.S. stock market drifted higher in tentative trading ahead of a deadline President Donald Trump has set to bomb Iranian power plants.

The S&P 500 rose 0.4% Monday. The Dow Jones Industrial Average added 0.4%, and the Nasdaq composite climbed 0.5%.

Like stock indexes, oil prices seesawed through the day amid continued uncertainty about what will happen in the war with Iran and how long it will slow the global flow of crude oil. Trump warned again he will bomb Iran’s power plants if it doesn’t open the Strait of Hormuz.

On Monday:

The S&P 500 rose 29.14 points, or 0.4%, to 6,611.83.

The Dow Jones Industrial Average rose 165.21 points, or 0.4%, to 46,669.88.

The Nasdaq composite rose 117.16 points, or 0.5%, to 21,996.34.

The Russell 2000 index of smaller companies rose 10.60 points, or 0.4% to 2,540.64.

For the year:

The S&P 500 is down 233.67 points, or 3.4%.

The Dow is down 1,393.41 points, or 2.9%.

The Nasdaq is down 1,245.65 points, or 5.4%.

The Russell 2000 is up 58.74 points, or 2.4%.