Stocks fell as the yield on the benchmark 30-year Treasury bond climbed above 8% for the first time since May 1992. Although interest rates in general have been trending up recently, today's move stemmed partly from the fact that the Treasury is due to auction off $28.25 billion worth of two- and five-year notes on Tuesday and Wednesday. Traders apparently feared that this influx of new issues could drive prices down, and yields up, especially with the Federal Reserve expected to lift short-term rates again as soon as next month. In response, the Dow Jones Industrial Average plunged 36 points to 3855.30 on moderate trading (N.Y.S.E. volume: 282 million shares). The S&P 500 fell 4.06 to 460.83. NASDAQ stocks dropped 4.17 to 761.21. And that 30-year Treasury ended the day at 8.04%, up from 7.98% on Friday. The price of gold fell 45 cents to $389.50 an ounce in London trading.