US stocks on Tuesday finished mostly lower with the Nasdaq dropping more than 0.5 per cent after the Federal Reserve warned that some technology stocks appear to be overvalued.
The Dow Jones Industrial Average inched up 5.26 points (0.03 per cent) to 17,060.68, while the S&P 500 fell 3.82 points (0.19 per cent) to 1,973.28.
The biggest losses came in the tech-rich Nasdaq Composite Index, which slumped 24.03 points (0.54 per cent) to 4,416.39.
Nasdaq fell as low as 4,389.70 earlier in the session after a Fed report to Congress said smaller stocks in social media and biotechnology "appear substantially stretched."
The report was released in conjunction with congressional testimony by Fed Chair Janet Yellen, who said the central bank could implement interest rate increases "sooner and be more rapid than currently envisioned" if labor market conditions continue to improve more than expected.
Art Hogan, chief market strategist at Wunderlich Securities, said Yellen's remarks on interest rates were "different" than what he expected and "sort of got my attention."
Otherwise, Yellen "pretty well stuck to the script," he said, noting that Yellen emphasized that the timeframe on raising rates was entirely data-dependent.
Leading technology and biotech names dropped, including Amgen (-1.8 per cent), Biogen (-2.4 per cent), Facebook (-1.1 per cent), Tesla Motors (-3.1 per cent) and Yelp (-2.9 per cent).
Nasdaq heavyweight Apple dropped 1.2 per cent.
Investors frowned on a complex deal in which US tobacco giant Reynolds American will buy Lorillard for US$27.4 billion and sell cigarette brands including Salem and Winston to British firm Imperial Tobacco for US$7.1 billion.
Reynolds sank 6.9 per cent, while Lorillard plummeted 10.5 per cent.
JPMorgan Chase led the Dow index higher, rising 3.5 per cent after reporting earnings of US$1.46 per share, well above analyst estimates of US$1.29.
Goldman Sachs, another Dow component, rose 1.3 per cent as earnings of US$4.10 per share beat analyst expectations of US$3.05. Strong results in underwriting and Goldman's own investments offset a hit from lower trading fees for clients.
The good banking results lifted Bank of America (+1.5 per cent), which reports earnings before markets open on Wednesday.
Bond prices were mixed. The yield on the 10-year US Treasury rose to 2.55 per cent from 2.54 per cent on Monday, while the 30-year held steady at 3.37 per cent. Bond prices and yields move inversely.