Stock market today: Dow, S&P 500, Nasdaq turn lower with oil prices, Walmart, rate-cut bets in focus

Group 1 - Oil prices have increased due to potential armed conflict between the US and Iran, with Brent crude and WTI crude rising around 2% to above $71.60 and $66.20 respectively, resulting in monthly gains exceeding 11% for both [1] - The oil market is reacting to the Trump administration's decision to deploy a second aircraft carrier to the region, marking the largest air power buildup in the Middle East since the Iraq invasion in 2003 [2] - Iran's foreign minister indicated that discussions with Washington may have reached a framework for a nuclear deal, while Ayatollah Ali Khamenei's social media account posted provocative comments regarding the negotiations [3] Group 2 - Iran possesses the third largest proved crude oil reserves globally and is among the top 10 producers, with significant attention on the Strait of Hormuz, a vital shipping route for approximately 20 million barrels of petroleum products daily [4] - The Iranian government announced a partial closure of the Strait of Hormuz for military exercises, which is significant as previous drills were conducted without formal closure notifications [4]