Broad-market indexes were higher. The NYSE composite index was up 0.87 point at 247.41. On the American Stock Exchange, the market value index was up 3.40 points at 413.47.
Investors are forsaking unattractively low bond yields for higher stock returns and pouring money into stock funds, stock analysts said.
The interest rate on the Treasury's benchmark 30-year bond sank to 6.78 percent from Tuesday's close of 6.84 percent. It was the lowest closing yield since the Treasury began selling the issue on a regular basis in 1977.
"As yields go down, that makes the value of stocks go up. That's been the driver," said A.C. Moore, a market analyst at Argus Investment Management.
"I just think there's an enormous amount of cash on the sidelines, and where's it going to go?" said Robert Kahan, manager of equity trading at Montgomery Securities. "It's not going into the long(-term) bond at 6 1/2 percent."
But analysts warned about the opposite reaction in stocks if Treasury market interest rates suddenly move higher, a reversal that some fear might take place.
David Bostian, chief economist at Herzog Heine Geduld, said the rates are falling on "mistaken assumptions" about the ability of the Clinton administration plan to cut the budget deficit and the extent of any economic slowdown.
"The bond market is basically blind to all that and could have a sharp short-term correction," he said.
The Standard & Poor's composite index of 500 stocks rose 1.367 points to 449.26. The S&P 400 industrials gained 0.97 to 516.35. The average NYSE share gained 12 cents.
The Wilshire Associates Equity Index - the market value of NYSE, American and Nasdaq issues - was $4,406.802 billion, up $20.073 billion, or 0.46 percent.