Moderna was the S&P 500’s top performer in August after reporting promising late-stage trial results for a personalized mRNA cancer vaccine co-developed with Merck. The data challenged doubts that Moderna could deliver another major breakthrough after the decline of its Covid-19 vaccine business. Enterprise software stocks also ranked among the index’s strongest performers, reversing earlier losses tied to fears that accelerating AI development would undermine traditional software models. Palantir, Veeva Systems, Salesforce and ServiceNow had faced sustained selling pressure, intensified by large short positions held by Situational Awareness, a leveraged hedge fund run by Leopold Aschenbrenner. The fund peaked at $45 billion in assets at the start of July, used as much as 400% leverage and lost roughly $35 billion after margin calls from Bank of America, Goldman Sachs and JPMorgan Chase forced the distressed sale of its publicly traded holdings to Ken Griffin’s Citadel. Its late-July short covering helped lift targeted software shares. Salesforce recovered after stronger-than-expected quarterly results, while ServiceNow showed that AI could be integrated into its platform without disrupting existing operations. Veeva Systems and Gartner also benefited as anticipated AI pressure on their businesses failed to appear in company results. Outside software, Newmont rose with gold prices, Coinbase gained as cryptocurrencies rebounded amid concerns over U.S. debt and government spending, and Super Micro Computer and Sandisk advanced on demand for memory used in AI data centers. Moderna also raised $2 billion through convertible senior notes due 2032 to fund its cancer vaccine business.