Wall Street staged its strongest daily rebound since late May on Thursday after Moderna and Merck announced positive Phase 3 results for a personalized mRNA cancer vaccine, driving Moderna shares up 177% and Merck stock 13% higher.
The Dow Jones Industrial Average climbed 0.98% to 53,277, while the S&P 500 gained 0.43% and the Nasdaq Composite rose 0.43%. The rally came after Treasury Secretary Scott Bessent signaled readiness for more aggressive bond market intervention to contain borrowing costs.
The US national debt surpassed $40 trillion, adding fiscal pressure as uncertainty over US-Iran negotiations and the Strait of Hormuz standoff kept energy markets volatile. Tesla advanced after Nevada regulators approved robotaxi operations in parts of the state. Target reported second-quarter sales growth of 5.3%, while Fed minutes showed officials open to rate increases if inflation persists.