Investors had two reactions to Israel's broad attack on Iran late Thursday: They sold stocks broadly and bought crude oil and gold. Futures trading suggests the Standard & Poor's 500 Index will open down 52 points.

Oil prices leaped, and stocks slumped on worries that escalating violence following Israel’s attack on Iranian nuclear and military targets could damage the flow of crude around the world, along with the global economy.

That sent the yield on the 10-year Treasury up to 4.43% from 4.36% late Thursday. Higher yields can tug down on prices for stocks and other investments, while making it more expensive for U.S. companies and households to borrow money.