WASHINGTON - The bond market is betting on a stronger economy.

Prices for U.S. Treasury debt plunged for the fifth straight trading session Wednesday, and the yield on the benchmark 10-year note spiked to its highest level since October.

Money poured out of bonds and into stocks after rosy words on Tuesday from the Federal Reserve gave traders confidence that the economic recovery is strengthening. Major stock market averages are at or near four-year highs.

Treasury yields - and interest rates that take their cues from Treasury yields, including mortgage rates - remain near all-time lows. So while mortgage rates may creep up, they should remain historically low.

Even with the economy getting stronger, the Fed plans to keep short-term interest rates near zero through 2014. And demand is strong for long-term Treasurys because the dollar and the U.S. government still look like safer bets than the euro and other nations.

More evidence of the hunger for U.S. debt came Wednesday afternoon, when the Treasury Department auctioned $13 billion in 30-year bonds. Bids came in higher than current market prices.

The bonds were priced to yield 3.38 percent. Similar bonds trading on the open market fetched a yield of 3.41 percent.

The yield on the 10-year Treasury note was 2.27 percent as of 4 p.m. Eastern time Wednesday. It hasn't closed above that level since Oct. 28, but the yield is far lower than the 3.36 percent level where it settled a year earlier.

Prices rose and yields fell for U.S. government debt almost all last year. Investors were willing to pay for the safety of U.S. debt because other investments, like volatile stocks and the euro, seemed much riskier at the time than they are today.

The interest rates that Americans and businesses pay on mortgages and other loans tend to track the 10-year note, and rising yields should make the interest rates on those loans increase.

With the spring home-buying season about to start, the average interest rate on the most popular mortgage loan, the 30-year fixed, fell last week to 3.88 percent, a hair above the 3.87 percent it hit three weeks ago. That was the lowest since long-term mortgages were popularized in the 1950s. A year ago, the average was 4.88 percent.

If mortgage rates rise from the all-time lows where they have coasted for months, fewer people will try to refinance their loans, said Greg McBride, senior analyst with Bankrate.com.

"It does have an impact on refinancing traffic, which is far more sensitive to every fluctuation in rates," he said. But McBride said rates are still "super-low," and homebuyers are unlikely to make decisions based on a move of a few hundredths of a percentage point.

Even if refinancing applications decline, he said, recent changes to the government's foreclosure-prevention programs will take up the slack by expanding the pool of people eligible for help.

Interest rates haven't been the main barrier to borrowing and lending in this sluggish economy. Banks say they're not getting enough applications from borrowers with good credit. Borrowers say banks' lending standards have tightened so much that almost no one can clear the bar.

In the bond market, traders have been selling bonds mainly because the Fed's view of the economy has improved markedly. The Fed said in a policy statement Tuesday that it saw signs of strength in hiring and spending by consumers and businesses. It appears less likely that the European debt crisis will cause financial upheaval here, the Fed said.

Later Tuesday, the Fed said that all but four of the 19 biggest U.S. banks are strong enough to raise their stock dividends and still be able to withstand a financial crisis worse than what happened in 2008.

When traders believe the economy is improving, they tend to sell bonds - which are relatively safe but offer limited returns - and buy investments such as stocks, which tend to rise in periods of growth.