US stocks closed lower on September 15, with all three major indices declining. Nvidia fell more than 3%, leading losses among top-traded names. Among the top 20 most actively traded US stocks, Nvidia stood out with its sharp drop, while several leading American AI executives called for a slowdown in technology development. Chinese ADRs were mixed, with Li Auto gaining over 3% and Pinduoduo falling more than 2%. In commodities, oil prices rose as a Saudi pipeline outage raised supply concerns, while bets on further rate hikes intensified. Copper and gold prices declined. European markets also retreated, pressured by a selloff in AI-related stocks and rising energy costs.

On the macro front, former President Trump stated he would issue a $5,000 dividend to all American adults. He also remarked that the US is currently producing more precision weapons than ever before, attributing inflation to the Biden administration. Trump claimed that aside from oil prices, prices are notably declining, and that oil prices will plummet after the Iran conflict concludes. He also stated that oil flows through the Strait of Hormuz remain normal. Additionally, Trump pushed back against calls to slow artificial intelligence development, alleging a "conspiracy" against AI and data centers. He further claimed that Russia and Ukraine had agreed to stop attacking energy infrastructure, though Kyiv said it was premature to say so. US House Speaker Johnson announced that Trump would convene AI executives this week or next. The 10-year Treasury yield broke above 5% for the first time since 2023, and Ukrainian President Zelensky indicated readiness to support de-escalation following a US proposal. In other news, two fishing boats were hit by drones off southern Iran, leaving several fishermen missing, and Saudi Arabia has requested British military and diplomatic support against Houthi attacks. Iran reported that a supertanker struck a mine in the Strait of Hormuz.

In corporate news, Trump met with the OpenAI CEO during the Republican convention. Bank of America forecast a more than 10% decline in Q3 investment banking fees, sending its shares down 5%. Apple released a redesigned Siri AI beta ahead of the iPhone 18 launch this week. Anthropic launched Claude for financial advisors, deepening its push into the financial sector. Major US bank stocks suffered heavy losses, influenced by Bank of America's CEO comments and AI-themed trading. Citigroup, Goldman Sachs, and JPMorgan raised their year-end Treasury yield forecasts. Microsoft joined the ranks of AI companies urging caution with frontier models. The Bank of America CEO projected Q3 trading revenue to be "relatively flat," triggering a sharp selloff in Wall Street megabank shares. Meanwhile, a Costco product surged 125% in price over two years, prompting the retail giant to impose purchase limits on members.

In commentary, Citadel Securities suggested that weak growth could cap upside for European bond yields. MRA strategists warned that the first wave of a Fed rate hike impact could send the S&P 500 down 10%. Global chip stocks tumbled amid AI slowdown concerns, and Apple unveiled Siri AI while Anthropic introduced Claude for advisors. US equities saw major indices slump as worries over AI development slowdown and inflation worries gripped the market. Brent futures rose on supply risks from a Saudi pipeline outage. In FX, the dollar index trimmed gains while the yen weakened. A famously accurate analyst said the Treasury selloff is not over, with contrarian bets on the 10-year yield hitting 5%. House Speaker Johnson said he would meet AI executives this weekend or early next week. European bond traders increased bets on ECB and BoE rate hikes amid surging oil and gas prices. Senator Vance noted that approximately 870,000 individuals accused of embezzling taxpayer funds are barred from federal loans. Zelensky said Ukraine is willing to stop attacking energy facilities, provided Russia does the same. Trump stated that countries that did not help should compensate the US after the Iran war. Fitch reported that the US private credit default rate hit a record high of 6.3%.