What: Shares of footwear company Crocs (NASDAQ:CROX) slumped for the second day in a row on Thursday, driven by an analyst downgrade from Piper Jaffray. This comes one day after the company lowered its sales guidance for the third quarter during an Investor Day event. At 1:35 p.m. Thursday, the stock was down about 14.5%.

So what: Piper Jaffray, which previously had a "overweight" rating on the stock, as well as a $17 price target, has downgraded Crocs to "neutral," slashing its price target to $12 per share. Piper cites concerns about Crocs' long-term guidance being pushed out, and stated that it believes that the stock is "dead money" for the foreseeable future.

This downgrade stemmed from Crocs' Investor Day presentation on Wednesday, where the company guided for third-quarter sales of $270 million to $280 million, with unfavorable foreign currency exchange rates and the decision to hold back $6 million of orders to certain China distributors cited as reasons behind the guidance cut. The consensus analyst estimate for third-quarter sales is $286.7 million.

Now what: Crocs did reaffirm its mid-term operating margin target, stating that it expects to reach a range of 10%-12% as early as 2018. From 2010 through 2012, Crocs averaged an operating margin of 12.3%, so this target certainly isn't unrealistic, but so far there has been no sign that a turnaround is taking hold. In the second quarter, Crocs' operating profit slumped by 60% year-over-year.

Piper still believes in the Crocs brand, but it's now clear that a turnaround is going to take a lot longer than the firm had previously assumed. Investors are leaving the stock for dead, and given Crocs' recent results and guidance, it's hard to blame them.

Timothy Green has no position in any stocks mentioned. The Motley Fool owns shares of Crocs. 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.