While there's a perfectly good explanation for it all, you have to respect Bear Stearns ( BSC) CEO James Cayne's timing. On Dec. 2, Cayne reportedly sold 100,000 Bear Stearns shares for total proceeds of $6.45 million, according to insider sale information reported to the Securities and Exchange Commission. What's interesting about the timing of the sale is that it took place three weeks before Bear is scheduled to report fourth-quarter earnings on Dec. 19. And the day of Cayne's sale coincided with the high-water mark for Bear's stock this month. Cayne sold shares held by either himself, or in a trust, at $64.53 apiece. The firm's stock has been sliding ever since. It closed Friday at $59.93 -- down 7% since Dec. 2. There's nothing necessarily wrong with corporate insiders selling stock. It happens all the time. But when top corporate executives sell shares at the top of the trading range, it's sometimes seen as a bearish indication. The conventional wisdom on Wall Street is that an executive wouldn't be selling shares if he thought the stock was going higher. Indeed, the stocks of several brokerages sold off this week in advance of the release of fourth-quarter earnings from Bear, Goldman Sachs ( GS), Lehman Brothers ( LEH) and Morgan Stanley ( MWD). Many brokerage analysts are expecting the four Wall Street firms, on average, to report rather lackluster earnings. The Thomson Financial/First Call consensus estimate is for Bear to report earnings of $1.23 a share, the same sum as in the third quarter and a 14% improvement over the year-ago period. An investment bank spokeswoman said Cayne's sale had nothing to do with the upcoming earnings release and wasn't a case of market timing. Rather, it's part of a process of regularly scheduled stock sales by Bear executives and other corporate insiders. Elizabeth Ventura, a Bear spokeswoman, said the end of the firm's fourth quarter on Nov. 30 is a designated period for corporate insiders to sell shares that they've earned from a "deferred income plan." She said the stock sold by Cayne is part of a deferred compensation agreement that prohibits him from selling for five years. "It happens every year," said Ventura. She said that's why there is always a good deal of stock selling by Bear insiders around the end of November. But planned or not, the timing couldn't have been better for Cayne.