Microsoft (MSFT) CEO Steve Ballmer sold about 50 million shares of his Microsoft stock for $1.34 billion, as reported in the Wall Street Journal (subscription required).

Let's listen to a fictitious exchange between Steve and his tax accountant: "Steve, you know you hold 408 million shares of Microsoft. For the end of the year tax adjustments, it's a good idea to sell some of it, say 50 million. Microsoft's earnings are strong. The mutual and hedge guys most likely will be buying. We can sell into that strength."

The market takes an upward turn, and the insiders head for the exits.

In the wake of the largest stock market rally in 71 years, according to Bloomberg, the sale of insider shares has reached its most aggressive levels in the past two years. Insiders of companies in the S&P 500 were net sellers for 14 weeks in a row. Six people at Amgen (NASDAQ: AMGN), for example, sold $8.2 million in company stock.

When the current CEO of a $500 million company sells 3.2 million shares of stock -- more than half of his holdings -- it's bound to raise some eyebrows.

So give True Religion Apparel (NASDAQ: TRLG) for not trying to slip that one through. Instead, the company took the unusual step of issuing a press release announcing the sales by founder Jeffrey Lubbell before the filing of the Form 4 with the SEC. Of course, it couldn't help using the press release as an opportunity at spin. Take a look:

Mr. Lubell sold these shares for two purposes: first, to fulfill an obligation due under the marital dissolution agreement with his former wife; and second, to continue his financial, estate and tax planning.

So that explains it! Except how much of it was to settle the marital dissolution agreement (Us poor folk call it divorce...) and how much of it was for "financial, estate and tax planning"?

And more importantly, what exactly is "financial, estate and tax planning"? Or better yet, what stock sale wouldn't fall under the umbrella of financial planning? Might he have sold the shares to build a house made of gold, buy an island, or take a vacation in outer space? Of course the shares were sold for financial purposes! Any transaction involving money is financial.

This press release looks like a pretty desperate attempt at damage control. It'll be interesting to see how the market responds.

Internet tycoon Barry Diller, who is splitting up his IAC/InteractiveCorp (NASDAQ: IACI) conglomerate, has been adding to his position in Expedia Inc. (NASDAQ: EXPE), the Internet travel site where he's also chairman.

According to Reuters, Diller exercised options to buy 9.5 million shares at $8.59, giving him a 27.7% stake in the company. Judging from the company's recent performance, he may be onto something.

Net income soared 69% to $99.6 million, or 32 cents per share, compared with $59 million, or 34 cents a year earlier, the Bellevue, Washington-based company said today. Revenue rose 24% to $759.6 million. When one-time items are excluded, Expedia said its earnings were 39 cents, beating the 37 cents expected by analysts surveyed by Reuters.

"Expedia succeeded on almost every financial metric during the third quarter," crowed an ecstatic Diller in the earnings release. "These are good results, and our ability to keep them coming depends on the right balance of investment and profitable growth -- and I think we've shown our ability to be in proper cadence with those levers throughout this year."

Though the results were impressive, I am still have my doubts about the online travel business because it's so price competitive. But investors clearly aren't as pessimistic as I am since Expedia shares are up more than 43% this year.

Comcast Corp. (NASDAQ: CMCSA) Chief Executive Brian Roberts sold some of his shares in the top cable company for the first time since 2004.

The sale of 350,000 shares was done for financial planning purposes and because he's planning to increase his philanthropic work, according to the Philadelphia Inquirer story I wrote. Wall Street seemed non-pulsed by the sale, which represents a small portion of Roberts' holdings. By mid-afternoon, shares of the Philadelphia-based company were trading up.

Wall Street seems bullish on Comcast. Four analysts have upgraded the shares since the start of the year. The median 12-month target price is $33.51, higher than the $27.43 where it recently traded.

But Comcast hasn't shown shareholders much love this year because pesimissim abounds about cable, particularly as it faces increased competition from telecom players including Verizon Communications Inc. (NYSE: VZ). Comcast shares have slumped about 3%, underperforming its main rivals.

Though Wall Street doesn't think this share sale is a big deal, that sentiment will change if more insiders start lightening their holdings.