U.S. stocks advanced Monday as renewed hopes for U.S.-Iran diplomacy drove crude oil to its steepest one-day decline since July 27. West Texas Intermediate fell 7.1% to $96.72 a barrel, while Brent dropped 7.6% to $104.82, sending the S&P 500 up 0.6% to 7,626, the Dow Jones Industrial Average up 1% to 52,308 and the Nasdaq 100 up 0.5% to 28,514. Iranian President Masoud Pezeshkian said the supreme leader had authorized the government to seek a negotiated resolution, while Vice President JD Vance sent a message to Mohsen Rezaei aimed at restarting peace talks. Lower energy costs lifted consumer and travel stocks: the U.S. Global Jets ETF gained 5.6%, Delta Air Lines rose 4.7% and the consumer-discretionary sector ETF climbed 3.2%. Amazon rose 4.7% after Phillip Securities upgraded the stock and raised its price target to $330 from $320, adding about $121 billion to its market value. Treasury yields declined, gold and silver gained, and Bitcoin fell 1.1% to $77,378. Stronger manufacturing data supported the market, although artificial-intelligence hardware stocks weakened after Marvell confirmed its $115 billion all-stock acquisition of Lumentum.