When a company's own insiders won't buy its stock, what does that tell you? To me, it screams that they have lost faith, something that should make investors very wary.

That point certainly has been proved by the non-buying-actions of Research In Motion's (Nasdaq: RIMM) top executives. None have reported buying RIM shares on the open market since 2010. Is it a coincidence then that its share price has fallen 60% since? Indeed, the only transactions they have made with RIM stock is to sell, at least 11 times in that time frame.

Given the problems that Research In Motion has had in keeping its customers from rushing off to the Apple (Nasdaq: AAPL) iPhone and to smartphones that use Google's (Nasdaq: GOOG) Android operating system, this does not inspire confidence.

Frankly, with RIM's price falling so much, it would seem like the perfect time for RIM insiders to pick up shares in their company at bargain prices. Executives from other companies have taken advantage of such opportunities. Dell (Nasdaq: DELL) CEO Michael Dell saw his company's shares fall by more than half in 2008. What did he do? He bought shares.

But wait …
There's a wrinkle in this scenario. Something made RIM shares shoot up 18% on Wednesday, and it certainly wasn't euphoria over sovereign Greek debt. Could a takeover be brewing? That could be one reason there's been no executive buying lately. Insiders are barred from such action if takeover talks are going on.

The U.K.'s Independent newspaper reported yesterday rumors that Vodafone (Nasdaq: VOD) could be "one of the potential aggressors" targeting RIM and that there were also "vague rumors" that RIM had asked "an investment bank to consider various strategic options."

Is there a bottom line here?
Those are just rumors, mind you. And I have to ask what another company -- especially a wireless carrier like Vodafone -- would see in the BlackBerry maker. Becoming a phone producer doesn't sound like a good fit.

RIM is still profitable, thanks to its longtime corporate customers, but its efforts to compete with the iPhone and the Android phones have been too little, too late. Unless it can come up with a killer reason why those clients should stick with the BlackBerry, RIM's future is murky. At least that's what Research In Motion executives are signaling to me.

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Fool contributor Dan Radovsky has no financial interest in the above-mentioned companies. The Motley Fool owns shares of Apple, Google, and Research In Motion. Motley Fool newsletter services have recommended buying shares of Dell, Apple, Vodafone Group, and Google and creating a bull call spread position in Apple. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.