NEW YORK — Investors are finding fresh reasons to bet on an economic rebound.

Stocks rose today as gains in commodities like oil and natural gas signaled that traders expect a strengthening economy will demand more energy.

Robust demand at an auction for Treasury debt also eased fears that the government would have to pay higher interest rates to entice buyers. Higher rates on long-term bonds would also drive up borrowing costs for consumers buying cars and homes, which in turn could endanger an economic recovery.

It was the second straight day that interest rate movements called the shots in the stock market, and not likely the last.

Analysts expect Wall Street will have to continue to grapple with worries that the government could eventually exhaust buyers' appetite for debt with an unprecedented level of bond sales. Washington needs to raise the money to pay for its bank rescue plan and economic stimulus spending.