"I think the number is close to $50 billion," said John D. Lyons, executive managing director of Granite Partners, a real estate investment firm.

"People are coming back to the market because they believe the risk has been underwritten," or discounted, said Mr. Lyons of Granite Partners.

Demand is up and vacancy rates are down, said John Lyons, a founder of Granite Partners, a real estate investment bank.

"The development climate in Philadelphia is unlike anything I've seen there in a decade," said Gerard Mason, senior managing director of Granite Partners.

The low interest rate climate should continue through this year, at least until the presidential election, said John Lyons, the president of Granite Partners, a financial consulting company.

As hedge funds like Granite Partners have had to dump bonds, prices have plunged and buyers have headed for the hills.

"There's a tremendous amount of uncertainty at the moment," said John D. Lyons, executive managing director of Granite Partners, a real estate investment bank.

The bridegroom, 37, is a senior vice president of Granite Partners, a commercial real estate investment bank in New York.

There is plenty of capital available to finance purchases, said John D. Lyons, executive managing director of Granite Partners, a real estate investment banking firm.

"This would break the record for trophy buildings," said Gerard Mason, executive managing director of Granite Partners, a real estate investment bank that tracks building sales nationwide.