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's happening: Shares of Blue Nile (NASDAQ:NILE) had dropped more than 13% as of 1:30 p.m. Tuesday after the online jewelry specialist announced weaker than expected fourth-quarter results.

Why it's happening: Quarterly revenue rose 7.9% year over year to $157.4 million, which translated to net income of $4.8 million, or $0.41 per diluted share. Analysts, on average, were looking for earnings of $0.44 per share on sales of $164.4 million.

Blue Nile also provided guidance for current-quarter net sales between $107 million and $110 million, and earnings per share of $0.07 to $0.09. The midpoint of both ranges is below Wall Street's expectation for EPS of $0.11 on sales of $114.3 million.

Finally, for full fiscal 2015 (ending Jan. 3, 2016), Blue Nile anticipates net sales between $488 million and $505 million, and earnings per share of $0.83 to $0.93. Analysts were modeling fiscal 2015 earnings of $1 per share on revenue of $523.2 million.

Even so, Blue Nile CEO Harvey Kanter reminded investors the company's fourth-quarter growth continued "positive momentum from Q3 in spite of what was a challenging quarter for many jewelry retailers." He went on, "While these results are below our expectations, the above-industry growth demonstrates that we made progress and gained share."

In the end, while it's hard to blame the market for bidding down shares today, Blue Nile and its shareholders still appear well-positioned to benefit from the long-term trend of more consumers buying big-ticket jewelry items online.