Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of electric vehicle maker Tesla Motors (Nasdaq: TSLA) zoomed as high as 12% in intraday trading after selling a $30 million stake to Japanese electronics giant Panasonic (NYSE: PC).

So what: Panasonic, which will acquire about a 2% stake in Tesla, said the two companies will combine efforts and sell battery packs for electric cars. Daimler and Toyota (NYSE: TM) have already made sizable bets on Tesla, so investors are taking the Panasonic deal as yet another powerful endorsement of Tesla's technology.

Now what: Tesla may eventually turn out to be a good green idea, but it seems too risky right now to get involved. While the recent big-boy buy-ins lend some credibility to Tesla's potential, the company hasn't been profitable since it was founded in 2003. With no real manufacturing experience and only 1,000 of its high-end cars sold, it's tough to envision how Tesla will ever have the edge over increasingly green-focused auto giants like Ford (NYSE: F) and Nissan.

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