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 home furnishings retailer Pier One Imports (NYSE:PIR) plunged on Wednesday after the company revised its full year financial guidance. A disappointing January and February, along with some unplanned expenses, led Pier One to slash sales and earnings guidance. Shares were down more than 20% on Wednesday following the news.

So what: Pier One had previously guided for mid-to-high single-digit comparable store sales growth for the full year, and EPS in the range of $0.95 to $1.05. This guidance, announced in September, actually cut the company's previous EPS guidance of $1.14 to $1.22. With this latest announcement, Pier One now expects EPS to end up between $0.80 and $0.83, a reduction of roughly one-third compared to the initial guidance. Comparable store sales are now expected to grow by 5% for the full year, which ends at the end of this month.

Sales in January and February ended up softer than the company was expecting, and unforeseen supply chain expenses are expected to eat into profitability. In addition to the guidance cut, Pier One announced that the company's Chief Financial Officer Charles H. Turner is retiring.

Now what: Pier One has been struggling with falling profits for three years now, and the guidance cut confirms that the company's attempts to reverse the trend have not worked so far. Earnings per share peaked at $1.48 in fiscal 2012, falling to $1.20 in fiscal 2013 and $1.01 in fiscal 2014, despite rising sales. Pier One's original guidance called for earnings growth this year, but a significant earnings decline will now take place instead. After the decline today, shares of Pier One have been cut in half since reaching a multi-year high in 2013.