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 BJ's Restaurants (NASDAQ:BJRI) were satisfying investors' appetites today, gaining as much as 16% after a strong second-quarter earnings report.

So what: The casual dining chain said revenues increased 10.5% to $219.4 million, essentially matching estimates at $220 million, though same-store sales fell 1.7%. While a decline in organic sales is usually a warning sign, investors were encouraged by a better-than-expected profit as adjusted earnings per share fell by a penny to $0.30, but beat estimates at $0.24. 

Now what: CEO Greg Trojan said he was "pleased" with the company's progress, noting initiatives to "reignite sales and improve operating performance." While the restaurant chain delivered a solid earnings beat, I think investors may be burying the lede here. Negative comparable sales and decreasing profit do not seem to warrant a double-digit jump in share price, especially for a company with a P/E of 59. Management guided comps for the current quarter to be flat, which is an improvement but not any more encouraging. The company's valuation is based on aggressive expansion, but without organic sales growth, it's hard to believe there's much demand for new locations. If comps remain low, I'd sell. 

Jeremy Bowman has no position in any stocks mentioned. The Motley Fool recommends BJ's Restaurants. 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.