Wall Street rises as yields ease, healthcare gains

The main US stock market indexes closed slightly higher on Wednesday, with easing government bond yields enhancing risk appetites and a notable rally in Moderna shares driving gains in the healthcare sector. Notably, Moderna's stock surged nearly 177% following a successful late-stage trial of its personalized mRNA cancer therapy developed in partnership with Merck, which demonstrated a reduction in melanoma recurrence and spread.

Merck's shares also rose by 12.6%, becoming the largest percentage gainers in both the Dow Jones Industrial Average and the S&P 500. This rally bolstered healthcare peers such as Novavax and BioNTech, with the latter's shares jumping 22%. The S&P 500 healthcare sector experienced its biggest one-day percentage gain since April 2025, closing up 3.5%.

Other sectors also contributed to the gains, with consumer discretionary adding 2%. However, equity indexes pared gains as the day progressed. Investors showed relief following the government's announcement of doubling the size of liquidity support buyback operations for longer-dated bonds, as concerns over government debt and inflation were alleviated.

Moderna's stock performance led the S&P 500 gainers in a record rally for the company, with other biotechnology stocks also experiencing significant increases.