The S&P 500 was unable to hold the 2,000 mark after moving above the milestone level for the first time on Monday, but still managed to close at a record high, buoyed by financials and biotechnology stocks.

The significance of the milestone was more psychological than fundamental, and it represents the high point of a nearly six-year rally that has boosted retirement accounts for Americans from Wall Street to Main Street, though the gains have largely benefited wealthier Americans. On a total-return basis the S&P 500 has more than tripled from its 2009 low hit during the financial crisis.

The day's gains were broad, with each of the 10 primary sectors on the benchmark S&P index advancing.