Wall Street benchmarks closed in positive territory on Wednesday, buoyed by a retreat in U. S. Treasury yields and a stellar performance from Moderna, which significantly lifted the healthcare sector. The Dow Jones Industrial Average gained 123.94 points, or 0.23%, to close at 53,467.34. The S&P 500 rose 18.15 points, or 0.24%, to end at 7,709.91, while the Nasdaq Composite added 40.08 points, or 0.15%, to 26,331.09.
The market found its footing as long-dated Treasury yields eased from recent multi-decade highs. This decline followed an announcement from the U. S. Treasury Department that it would double the size of its liquidity support buyback operations for longer-dated bonds. Specifically, the department will increase these operations from $2 billion to at least $4 billion per operation, effective from September 9 through November 4. The 30-year Treasury yield, which had recently touched its highest level since 2007, fell to around 5.18%.
A major driver of the day's gains was Moderna, whose shares more than doubled after the company announced positive Phase 3 trial results for its personalized mRNA cancer vaccine developed in collaboration with Merck. The vaccine, intisomeran autogene, showed a significant reduction in the risk of melanoma recurrence and spread. Merck's stock also saw a substantial boost, climbing 12.6% and becoming the top performer on the Dow Jones Industrial Average. This success in oncology marks a significant milestone for mRNA technology beyond its applications in infectious diseases.
The broader healthcare sector benefited from Moderna's breakthrough, with peers like Novavax and U. S.-listed shares of BioNTech also experiencing gains. The S&P 500 healthcare sector achieved a record high, providing substantial support to the benchmark index. However, the technology sector experienced some weakness, with chip stocks leading the decline, reflecting ongoing concerns about market concentration and the sustainability of AI-driven growth. Investors also parsed the minutes from the Federal Reserve's July meeting, which indicated continued concern over inflation, though expectations for an immediate September rate hike had diminished.
