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 car specialist Tesla Motors (Nasdaq: TSLA) were zooming ahead today, gaining as much as 12% in intraday trading after a Wall Street upgrade.

So what: Analyst Theodore O'Neill of Wunderlich Securities was behind Tesla's zippy performance today, as he upgraded the company's stock from hold to buy and boosted his price target for the shares from $30 to $49. The jolt of optimism came after O'Neill toured Tesla's Fremont, Calif., facilities and realized that management's production goals for 2012 aren't nearly as aggressive as he'd previously assumed. In fact, O'Neill posited that there's "no reason from a production standpoint why it can't immediately ramp to 5,000 cars per quarter."

Now what: Undoubtedly that's a great vote of confidence and a nice price-target boost -- O'Neill's $49 target suggests that there's still 30% of additional upside even after the jump in the stock price today. On the flip side, though, it's key for investors to bear in mind that this is just the view of a single analyst. While it's worthwhile to take O'Neill's bullish take into account when formulating your own thesis on Tesla, jamming down the buy button on the basis of just a single analyst viewpoint is not a Foolish way to go.

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