NEW YORK, Aug 16: US stocks rose slightly on feather-light volume on Friday, as Wall Street regrouped after the biggest-ever power failure in North America.

Wall Street firms switched on their emergency power systems and electronic dealing systems, enabling them to run normally on a day when many stores and offices in New York remained shut because they lacked electricity. But with thousands of office workers stranded outside the city, trading volume across all markets was woefully thin — even thinner than on a usual Friday in August.

“It’s very, very quiet. Virtually nothing’s going on,” said Tim Smalls, managing director at S.G. Cowen. “Everyone’s running on a skeletal staff today.”

The blue-chip Dow Jones industrial average edged up 11.13 points, or 0.12 per cent, to finish at 9,321.69. The broad Standard & Poor’s 500 Index added just 0.16 of a point, or 0.02 per cent, rising to 990.67. The tech-laden Nasdaq Composite Index ended up 1.66 points, or 0.10 per cent, at 1,702.00, based on the latest available data.

For the week, the Dow rose 1.42 per cent, the S&P 500 gained 1.34 per cent, and the Nasdaq advanced 3.53 per cent.

“Normally you’d see a lot more volatility, since we also have options expiry today. But there’s so many connectivity problems, most people decided to watch and wait instead of be actively trading today,” said Jeff Swensen, a senior trader at John Hancock Advisers.

Friday marked the expiration of August individual equity options and some stock-index options, which often leads to additional volatility in stock prices and the market.

Just 699.2m shares traded on the Nasdaq, making it the lightest trading day so far this year.

Volume was also extremely light on the New York Stock Exchange, with just 562.6 million shares changing hands, compared with an average daily volume of 1.45 billion.

The New York Stock Exchange and Nasdaq opened normally at 1330 GMT, and closed as usual at 2000 GMT.

But the bond market closed early at 1800 GMT on the recommendation of the Bond Market Association because of the difficulty bond market employees had getting to work. The American Stock Exchange began trading in late afternoon, and said it started receiving orders around 1945 GMT.

On the Nasdaq, shares of alternative energy companies posted some of the largest gains in the wake of the blackout.—Reuters