Wall Street stocks finished at all-time highs for a second straight day on Thursday on a mix of optimism about the economy and Federal Reserve policy, offsetting a big drop in Apple shares.

All three major indices climbed to fresh records, led by the Dow Jones, which moved nearer to 40,000 points.

Analysts said the gains partly reflected market relief after the Fed continued to signal it expects interest rate cuts this year.

Equally important, there's just as "much excitement about this market" on the basis of economic fundamentals, said Art Hogan of B Riley Wealth, citing strong existing home sales data as further corroboration of a solid economic outlook.

The Dow Jones finished at 39,781, up 0.7 percent.

The S&P 500 advanced 0.3 percent to 5,241, while the Nasdaq added 0.2 percent at 16,401.

The gains came despite a 4.1 percent drop in Apple shares after the tech giant was sued by the Department of Justice over allegations it illegally maintained a monopoly for its iPhone by stifling competition and imposing exorbitant costs on consumers.

But that downer was countered by a flourishing trading debut for social media company Reddit, which soared 48 percent after pricing at the top of its range in an initial public offering.

The strong performance by Reddit lifted expectations of other IPOs, benefitting large banks, including Goldman Sachs, which jumped 4.3 percent.

Micron Technology surged more than 14 percent after reporting earnings that exceeded company projections and touting its future prospects. (AFP)