Stock sales by America's corporate leaders exceeded purchases last month by the widest ratio in nearly 20 years. Executives sold $63.18 of shares for every $1 they bought in November, the largest ratio since at least January 1987. U.S. securities laws require company executives and directors to disclose stock purchases or sales within two business days. Insiders sold $8.4 billion in shares last month, according to data compiled from SEC filings. Buying was ... $133 million. The overall insider-selling amount was the fifth-highest since 1987. Selling peaked at $13.9 billion in March 2000. The data have value for investors," said Wayne Reisner at Carret Asset Management in New York. "It's people who are very familiar with their company and their stock." Insiders executed 6.34 sales transactions for each purchase transaction in the eight weeks ended Dec. 1. That's up from 2.45 in the period ended Aug. 4 and above the ratio of 2.25 he considers neutral for the market. Microsoft ranked first among U.S. companies, with $594.2 million in sales by insiders in November. Seagate Technology and DreamWorks Animation SKG Inc. ranked second and third, at $311.8 million and $224.2 million, respectively. Google Inc. was fourth, at $182.1 million.