U.S. equities closed slightly lower on Monday, but held near record levels, while shares of Apple declined on a rare downgrade.
The S&P 500 slipped 1 percent, with materials and utilities lagging. The Dow Jones industrial average fell about 20 points, with Apple contributing the most losses. The Nasdaq composite traded 0.1 percent lower after reaching an all-time intraday high.
Rob Lutts, chief investment officer at Cabot Wealth Management, said two key elements supporting this market are the relative value of stocks versus other alternatives, like bonds, and strong earnings growth.
"Clearly the market is more expensive compared to a few years ago, but earnings have justified those valuations," he said.
Still, some traders are worried about this stock-market rally as a large chunk of this year's gains have come from just five large-cap tech stocks.
"The averages are making new highs but that's because of a handful of stocks. If you take those out, we'd probably be lower," said Peter Cardillo, chief market economist at First Standard Financial.