While Fools should generally take the opinion of Wall Street with a grain of salt, it's not a bad idea to take a closer look at particularly stock-shaking analyst upgrades and downgrades -- just in case their reasoning behind the call makes sense.

What: Shares of Align Technology (NASDAQ:ALGN) sank 4% today after Baird Equity Research downgraded the purveyor of invisible braces from "outperform" to "neutral."

So what: Along with the downgrade, analyst Jeff Johnson reiterated his $49 price target on the stock, representing just 2% worth of upside to yesterday's close. While Johnson remains bullish on Align's earnings prospects, he believes that the stock's steady run-up in 2013 leaves investors with little upside to work with.

Now what: Baird still expects solid near-term growth out of Align.

"Downgrading ALGN to Neutral is not meant to be a call on the company's 3Q, especially as our intra-quarter checks have been generally positive and we still expect modest upside to our/Street's projections this quarter," noted Baird. "Further, we continue to like that management has seemingly gone on the offensive recently in both the high- (G4/SmartTrack) and low-acuity (Express 5/Realine) segments of orthodontics."

With the stock up about 65% in 2013 and trading at a forward P/E of 30, however, I'd agree with Baird's assessment that those prospects are already baked into the valuation. 

Fool contributor Brian Pacampara has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not 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.