Wall Street closed out a banner August with a mixed session Monday, with tech shares propelling the Nasdaq to another record and a newly-tweaked Dow index retreating.

The tech-rich Nasdaq Composite Index gained 0.7 percent to score its second straight record after weeks of repeated records, closing at 11,775.46.

The Dow Jones Industrial Average dropped 0.8 percent to end the day at 28,430.05, but still enjoyed its best August since 1984. And the S&P 500 retreated from its latest record, losing 0.2 percent to finish the month at 3,500.31 in its best August since 1986.

In spite of the Dow's drop, it was "still a pretty good month," said Art Hogan, chief market strategist at National Securities. Monday's pullback simply reflects "the ebbs and flows of the market."

Hogan expects light trading volume throughout the week, traditionally a vacation period ahead of the Labor Day holiday.

The gains in August have followed extraordinary fiscal and monetary measures to boost the coronavirus-battered U.S. economy and have come as investors have shrugged off a partisan stalemate in Washington that has blocked progress on another big spending package.

Federal Reserve Vice Chair Richard Clarida on Monday described as "critical" a shift in the U.S. central bank's monetary policy to allow higher inflation to maximize employment.

The final trading session of the month was the first with new Dow components, Amgen, Honeywell International and Salesforce. Amgen and Salesforce both gained, while Honeywell was among the industrial giants to fall.

Airlines also were broadly lower after both Delta Air Lines and United Airlines eliminated change fees for U.S. travel. Both carriers fell more than three percent following the announcements.