Stocks set for modest gains

NEW YORK (CNNMoney.com) -- U.S. stocks were poised for a cautious but positive start Friday in light trading volume, ahead of a speech by Federal Reserve Chairman Ben Bernanke.

At 8:30 a.m. ET, Dow Jones industrial average, Nasdaq 100 and Standard & Poor's 500 futures were slightly higher.

Futures measure current index values against their perceived future performance and offer an indication of how markets may open when trading begins.

Dave Rovelli, managing director at Canaccord Adams, said there could be some volatility stemming from the expirations of stock options, but that's one of the few potential market movers on the horizon.

"Unless Uncle Ben (Bernanke) says something [negative,] or we get a bad home sales number, we're going to drift higher," said Rovelli. "On days where there's very low volume, people are afraid to short stocks, so day trading momentum should take stocks higher."

Rovelli said trading volume this week is down 60% from the same week last year.

"Everybody's at the Hamptons or the Jersey shore," said Rovelli. "Nobody's buying stocks. It's so dead out there."

Economy: Bernanke is due to speak at the Kansas City Fed Economic Symposium in Jackson Hole, Wyo., at 10 a.m. ET. The title of Bernanke's speech is "Reflections in a Year of Crisis."

A report on existing home sales is on tap, as is state employment data from the U.S. Labor Department. Sales of existing homes are expected to have risen to an annual rate of 5.1 million in July from 4.89 million the prior month, according to a consensus of economist opinion from Briefing.com.

World markets: China shares ended in positive territory, but stocks in Japan and Hong Kong fell.

European markets were modestly higher in morning trading, following reports that the European manufacturing industry showed signs of moderate growth for the first time in 15 months, according to Markit Economics, with job market declines slowing down for the first time since October.

Money and oil: The dollar fell versus major international currencies, including the euro, the yen and the British pound. The price of oil rose $1.07 a barrel to $73.98.