Updated from 4:12 p.m. EDT

The Dow drifted up in Wednesday's final hour of trade to close positive along with other major indices as an upbeat earnings season ultimately lured cautious buyers after Federal Reserve Chairman Alan Greenspan provided more hints of higher interest rates to come.

The Nasdaq led gains, adding 17 points, or 0.86%, at 1995.63; the S&P 500 gained 5.96 points, or 0.53%, to 1124.09; and the Dow finished up 2.77 points to 10,317.27. In other assets, the 10-year Treasury note moved up 5/32 in price to yield 4.44%, while the dollar was at a five-month high against the euro and trading up against the yen.

Volume on the New York Stock Exchange exceeded 1.7 billion shares, and decliners outnumbered advancers by about 5 to 4. Over 2 billion shares changed hands on the Nasdaq, where advancers outpaced decliners by about 3 to 2.

Airline stocks led the market higher during Wednesday's session, with the Amex Airline Index closed up 2.5%. The Philadelphia Semiconductor index rose 1.9%, the iShares Dow Jones Healthcare basket climbed 1.1% and the Amex Network Index gained 2%.

The Dow's move was held back by Alcoa ( AA), which fell more than 3.9% on a broad decline in mining and precious metals, and United Technologies ( UTX), which dropped 2.8% despite better-than-expected first-quarter results.

In testimony before the Joint Economic Committee, Greenspan said inflation is not yet building but the Fed would act to limit it by raising the fed funds rate when needed. He said the broad economy is strong.

In addition, San Francisco Fed President Robert Parry told an audience Wednesday at Gettysburg College in Pennsylvania that interest rates will rise "significantly at some point."

Following Greenspan's testimony, the Fed's Beige Book report described economic growth as widespread, inflation modest and the job market tightened with modest wage gains.

"I think it's interesting that there's not a lot of follow-through to all the selling that happened yesterday," said John Hughes, equity strategist at Shields & Co. "It means it may have just been a knee-jerk reaction. I think the market's recent weakness is more transitional than anything else. The important thing is that the economy is beginning to recover and I think this is just part of the corrective process.

"The market knows that higher rates are coming and it's just trying to figure out what that is going to mean," he added.

Rate fears and further global instability wreaked havoc on commodities. Silver futures plunged 11.2% and copper lost 6.2%, while crude oil and gold prices each dropped close to 2%.