S&P closes above 1,900 for first time

The S&P 500 stock index closed above 1,900 for the first time in its 57-year history Friday.

Investors headed into the Memorial Day weekend on an optimistic note, as all three major stock indices post strong gains on Friday. Markets are closed Monday.

The S&P 500 was up roughly 0.4 percent at the close of trading Friday, while the Dow Jones Industrial Average and the NASDAQ posted gains of 0.4 and 0.75 percent, respectively. All three indices were also up strongly for the week, after going through a rocky stretch this spring.

While the economy posted dismal growth numbers in the first quarter of the year, there appears to be lingering optimism about the trajectory of the U.S. economy. Federal Reserve officials have stuck with their plan to slowly wind down the amount of stimulus they are pumping into the economy despite the slow growth in the winter months. Fed Chairwoman Janet Yellen has attributed much of that slowdown to the severe cold from the winter, although she has noted broader economic concerns, particularly with the high number of long-term unemployed.

Despite some economic concerns, the stock market has posted an incredibly strong run in the last year or so. Both the S&P and the Dow have posted new all-time highs, and the NASDAQ has neared highs it reached at the peak of the tech boom at the turn of the century.