Benedek Investment Group, a 2-year-old investment firm in New York, has provided seed money to startup entertainment companies, including Broadcast Interactive Media and Channel M. Now, it’s betting on real estate.

The firm, founded by 32-year-old Stephen Benedek with profits from the sale of his family’s broadcasting company, is financing the construction of four houses in the Hamptons, the summer resort on the eastern tip of Long Island that attracts movie stars and Wall Street executives. The first of his Southampton homes is on sale for $6.9 million.

Investors are treating American homes like stocks and bonds – a chance to make a trading profit. Real estate investors accounted for about 9% of home purchases in 2004, up from 6% in 2003, according to Fannie Mae, the world’s largest mortgage financier. In some markets, the share was as high as 30%.

“People have been putting more money into housing than they normally would because they’re so disillusioned with the stock market,” said Roger Kubarych, 60, a former Federal Reserve economist who’s now a senior adviser at HVB America.

Sales of new homes rose 12.2% in March to an annual rate of 1.43 million, according to a report this week from the U.S. Commerce Department. The gain was aided by 30-year mortgage rates averaging 5.9%.

The median house price, which fluctuates depending on which regions are strong and the types of homes being sold, rose 1.3% to $212,300 from a year earlier. The number of new homes for sale fell to 433,000 at the end of March, a one-year low.

“The timing is perfect,” Mr. Benedek said yesterday in an interview, referring to his Long Island project.

About 1.15 million homes will be sold this year, second only to the record 1.2 million sold in 2004, according to a forecast by the National Association of Home Builders.

Some policy-makers and homebuilders are concerned that the influx of investors is helping to overheat the residential real estate market.

“A couple of years ago, I was fairly confident that the rise in real estate prices primarily reflected low interest rates, good growth in disposable income and favorable demographics,” Federal Reserve Governor Donald Kohn, 62, said in an April 22 speech at Bard College in Annandale-on-Hudson, N.Y. “Prices have gone up far enough since then relative to interest rates, rents and incomes to raise questions” about whether the market is headed for a decline, he said.

D.R. Horton Inc., the largest American builder by stock-market value, is enforcing a strict “no investors” policy for all its developments.

When buyers place an order for a house, they sign a statement confirming that they aren’t investors. Real estate brokers involved in transactions also sign affidavits saying they aren’t representing investors. If the statements turn out to be false, the brokers could lose their real estate licenses.

“Every weekend on TV there are at least a half a dozen infomercials about turning a quick profit in real estate,” said Joseph Carreiro, a lawyer who teaches a class for real estate investors in Cambridge, Mass. “Sometimes that fast buck turns out to be very expensive if you dive in without knowing what you’re doing.”