Sugar jumped 3% and oil more than 1% on Wednesday after the Federal Reserve's pledge to keep interest rates low hit the dollar, making commodities cheaper for users of other currencies.
The dollar fell against the euro and yen after Fed Chairman Ben Bernanke dampened speculation that monetary tightening was near.
The drop in the currency didn't benefit all commodities. A few — gold, cotton, orange juice — closed lower because of their own weak supply-demand fundamentals.
The 19-commodity Reuters-Jefferies CRB index, dominated by crude oil and other energy components, rose nearly 1% for its first positive move in three sessions.
"Confidence is still fragile," said David Thurtell, a Citigroup analyst. "With any recovery, you're always going to get two steps forward, one step back."
Sugar prices climbed amid signs of increased demand in the physical market, especially after news that Pakistan had bought 50,000 metric tons of white sugar in a tender.
Failed sugar tenders in Pakistan and Egypt earlier this week gave raw sugar futures in New York their biggest one-day loss in nearly two years.
"Prices have now come down very significantly, so if there is import demand left, and I would expect there to be, then buyers such as Pakistan and India should come to the market now," said F.O. Licht sugar analyst Stefan Uhlenbrock.
Jack Scoville, an analyst at Price Futures Group, agreed.
"All these (markets) have been beat up pretty bad," Scoville said. "Sooner or later, this (selling spree) has got to subside."
New York raw sugar for May settled up 0.72 cent at 24.40 cents a pound. London white sugar for May finished at $673.70 a metric ton, up $19.80.
In oil, benchmark front-month crude rose $1.14 to $80 a barrel. London Brent crude rose 84 cents to $78.09 a barrel.
Traders said oil rose as Bernanke's comments weighed on the dollar and lifted equity markets, defying bearish data on crude inventories from the Energy Information Administration.
The EIA's weekly inventory data showed a larger-than-expected build in crude inventories last week because of higher imports. Stockpiles of distillates, which include diesel and heating oil, also fell by less than forecast in the week to Feb. 19.
"These were bearish inventory numbers," said Addison Armstrong, an analyst at Tradition Energy. "But it looks like the more Bernanke talks, the lower the dollar goes and the higher equities go and that is what crude is reacting to."
