US stocks ended Tuesday in mixed fashion after a stream of generally lackluster earnings reports and a modest upgrade to the International Monetary Fund's economic forecast.

The Dow Jones Industrial Average fell 44.12 points (0.27 percent) to 16,414.44.

But the broad-based S&P 500 rose 5.10 (0.28 percent) to 1,843.80 and the tech-rich Nasdaq Composite Index jumped 28.18 (0.67 percent) to 4,225.76.

Alec Young, global equity strategist at S&P Capital IQ, said the first batch of earnings reports has been "a little underwhelming," with fewer than usual companies beating expectations.

Other companies beat expectations, but gave outlooks that suggested mediocre earnings growth prospects.

"Given the moves that we've seen, people are waiting for fundamentals," Young said. "They want to see the fundamentals justify further gains."

The IMF raised its estimate for world economic growth in 2014 by a tenth point to 3.7 percent.

The IMF said the global economic recovery is strengthening. At the same time, the Fund said, the rebound in advanced economies is uneven and it warned of the threat of deflation.

Dow component Johnson & Johnson fell 1.1 percent after reporting net income of $1.23 per share, three cents above analyst expectations. But the company forecast 2014 earnings of $5.75-$5.85 per share, whereas analysts project $5.85.

Fellow Dow component Verizon Communications dipped 1.3 percent despite posting earnings of 66 cents per share, more than the 62 cents forecast. Cantor Fitzgerald said the company's commentary suggested clients in the private sector are hesitating on new investments.

A third Dow component, Travelers, reported earnings of $2.68 per share instead of the projected $2.16, yet dipped 1.7 percent amid concerns about the pricing of some products.

Dow Chemical shot up 6.6 percent after activist hedge fund Third Point took a stake in the company and said it was pressing management to spin off petrochemical assets and launch a share buyback.

Delta Air Lines jumped 3.3 percent after earnings came in at 65 cents per share, two cents above expectations. Traffic rose 2.0 percent in the most recent quarter.

Aluminum company Alcoa rose 6.8 percent after JPMorgan Chase upgraded the stock on a tightening market for the metal.

Bond prices were mixed. The yield on the 10-year US Treasury held steady at 2.83 percent, the same level as Friday. Markets were closed Monday for a federal holiday. The yield of the 30-year bond slipped to 3.74 percent from 3.76 percent. Bond prices and yields move inversely.