US stocks ended mixed on Wednesday as gains in the S&P 500 and Dow, both up 0.3%, were offset by technology and banking losses that pushed the Nasdaq 100 lower. The Treasury doubled its limit for buybacks of long-term securities for the next quarter, adding to measures aimed at containing the recent rise in longer-term benchmark borrowing costs. The intervention also raised expectations for greater dollar liquidity, supporting equities alongside lower rates. Minutes from the FOMC (Federal Open Market Committee) indicated that some officials considered rate hikes appropriate this year. Retail shares generally advanced after earnings from TJX, Target and Lowe's. Merck gained 12% and Moderna surged 150% after a trial of their joint melanoma vaccine reduced recurrence. OpenAI's tepid results weighed on chipmakers, with AMD and Intel each falling 4%.