Has Lululemon Athletica (LULU) - Get Report stock been stretched too far? The market will decide on Thursday when the yoga apparel company reports fiscal second-quarter earnings before the opening bell. Don't leave things to chance. Take your profits.

Since June 7, LULU has surged as much as 20%, trading from around $68 to as high as $81.81 on Aug. 25. The shares, currently at $76.85, have skyrocketed 46% for the year to date, crushing the returns of the S&P 500 (SPX) index and the sector exchange-traded fund, the SPDR S&P Retail (ETF) (XRT) - Get Report .

But how much higher can the stock go? More to the point, this stock is not cheap. Its recent gains, including an 19% rise over the past three months, have pushed LULU's forward price to earnings multiple to around 36, which is about 19 points higher than the S&P 500. Even when projecting out to fiscal 2017, the P/E drops to 30, which is still almost twice the forward P/E of the S&P 500.

Locking in some gains now would be a wise move, given that few retailers have survived the wrath of the market this earnings season. Even if Lululemon's results do meet analysts estimates, it might not be enough given that the stock is just 6% under its all-time high. This means the company would need breathtaking results and solid guidance to send the shares higher.

On the positive side, revenue grew 17% in its first quarter and management updated its fiscal 2016 revenue guidance to a range between $2.30 billion and $2.34 billion, which was a slight upgrade from the prior guidance of $2.29 billion to $2.34 billion. First quarter same-store sales grew by 5%, suggesting Lululemon continues to benefit from better merchandising without sacrificing margins.

Nonetheless, the market tends to apply selective memory when it comes to certain metrics. In this case, Lululemon would need to show growth acceleration in revenue and same-store sales in order to keep the stock from falling. That's just too much pressure for this stock.

This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.