Any time corporate executives and directors are heavily selling their company's stock there's reason for concern. And lately they've been doing just that. The last time insider selling was as high as it is now was in the period from late 2006 to late 2007. It was right after that insider-selling surge that the stock market began its long painful decline, says Charles Biderman, CEO of TrimTabs, an independent institutional research firm. Biderman believes that insider trades shoot higher when there's a disconnect between broad market opinions and what business executives feel in their gut. When [insiders think] things are going better than most people think, they buy stock," he says. "When things are going worse than people think, they sell." That's to say, insiders have no crystal ball but they often have access to up-to-the-minute sales data as well as firsthand impressions from their sales managers - and that gives them an inside track on what's happening in the economy. When this special access leads them to be big sellers of their stock, well, it's a vote of no confidence in their employer's near-term future. Biderman has measured the ratio of insider selling to buying since 2004, and says historically the ratio is 7 to 1. (Insiders almost always sell more than they buy because they receive stock as part of their compensation.) Right now the ratio is 30, one of the highest he's recorded. November 2007 is the last time the ratio even came close, at 24.