Shares of oil companies were some of the S&P 500's top gainers Tuesday as investors evaluated fresh developments in the conflict between Israel and Iran.

China is continuing to build up crude oil stockpiles as it refines substantially less than what it has available from imports and domestic production.

Despite heightened tensions between Israel and Iran and resulting market speculation, oil supply from the Middle East remains largely unaffected, with the critical Strait of Hormuz staying open for navigation.