It started out innocently enough. Back on July 23, The Wall Street Journal reported that Genzyme (Nasdaq: GENZ) and sanofi-aventis (NYSE: SNY) were in casual talks to see whether a price could be agreed upon.

Since then it has been rumor after rumor from this unnamed source and that unnamed source -- who knows, maybe they're all the same source. Here's a rundown, although I can't guarantee it includes all the rumors:

  • The Journal reported that GlaxoSmithKline (NYSE: GSK) and Johnson & Johnson (NYSE: JNJ) also might be interested. Glaxo was supposed to have told Genzyme to "keep us in mind," while J&J isn't saying.
  • Bloomberg reported that Genzyme "rebuffed" Sanofi's offer.
  • The New York Times, the Journal, and others report that Sanofi will send a "bear hug" letter, which defines the offer and makes it clear that Sanofi is willing to go hostile. The rumored value was at $70 per share.
  • The latest report from theJournal says the bear hug is off the table and Sanofi is in friendly talks with the company, reportedly offering $69 per share.

And that ignores all the opinion pieces, like Citigroup's analysts saying Sanofi may go hostile, Reuters running down why a white knight might not come in and outbid Sanofi, and Bloomberg saying that large shareholders -- Carl Icahn and Ralph Whitworth -- might demand $80 per share.

Granted The New York Times (NYSE: NYT) and News Corp. (Nasdaq: NWS) have to sell newspapers, but how is any of this helpful to anyone other than day traders? And who are the oft-quoted "people familiar with the matter" and what's their motivation? So far none of the rumors have actually amounted to anything.

How much is Genzyme worth? Whatever its board of directors is willing to let it go for. Retail investors will get a say if they have to approve the sale, but at that point it'll probably be too late to do anything. If things go hostile, investors might be able to tender their shares to Sanofi, but in those situations, the price on the open market can be higher than the hostile takeover price, implying that shareholders think the company is worth more.

What's an investor to do? If you don't own shares, I'd stay away. There's some upside if Genzyme can get a great price, but talks could break down and getting your news from unnamed sources may not be the most profitable venture. If you own shares, selling some or all might be worth considering. Of course if you have confidence in management's ability to turn things around, maybe it's worth holding through a downturn even if Genzyme can't be sold.

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Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. The Fool owns shares of GlaxoSmithKline and has a disclosure policy.