Although we don't believe in timing the market or panicking over daily movements, we do like to keep an eye on market changes -- just in case they're material to our investing thesis.

The stock market cooled off today, as both the S&P 500 Index and the Dow Jones Industrial Average broke four-day win streaks in the face of another massive winter storm. The wintery weather -- which has already committed the ultimate sin in the sporting world by forcing the postponement of the UNC-Duke college basketball showdown tonight -- poses a threat to traffic, commerce, and power lines on the East Coast. Still, Wall Street wasn't that intimidated, and the S&P lost just 0.5 points, or less than 0.1%, to end at 1,819 today. 

Despite only a modest downturn in the market today, shares of tobacco giant Lorillard (LO.DL) slumped 5% Wednesday, as fourth quarter earnings came in below estimates. While sales and net margins both rose in the period, the increases weren't quite what Wall Street expected. Lorillard only managed to boost revenue by 1.4% last quarter, and had to fight lower cigarette volumes with higher prices in order to do so. With the incredible amount of regulatory scrutiny facing this industry, this may be a trend investors have to get used to, as smoking in public becomes more stigmatized and retailers like CVS decide to consciously shun tobacco products. 

Big-box electronics retailer Best Buy (BBY 1.09%) also ended as one of the worst performers in the S&P, falling 2.1% Wednesday despite the lack of a significant catalyst. Best Buy shares right now are extremely susceptible to changing emotions in the market -- more so than the average stock -- because of its significant underperformance so far in 2014. It's down more than 37% this year, as Wall Street hasn't yet been able to forgive Best Buy for its abysmal same-store sales numbers over the holiday period, when the metric fell by 0.9%. While this may be an instance of emotions running wild and bearishness irrationally overpowering the upside case, the sales trend is indeed troubling and I'll be looking for sustainable revenue growth before adding this stock to my portfolio. 

Lastly, shares of $31 billion biotech Regeneron Pharmaceuticals (REGN -1.75%) lost 1.9% today, as today's profit-taking mood sent shares lower. Profit-taking was precisely the culprit in today's slight downturn, since the last major news to come out of the company was yesterday's blowout earnings report. Shares of Regeneron Pharmaceuticals, which have rocketed more than 750% in the past three years alone, have launched atmospherically higher primarily on the strong performance of its macular degeneration drug, Eylea. Total revenue surged 47% in the most recent quarter, and the blockbuster drug is expected to continue selling well in the coming year, as Regeneron forecast Eylea sales to come in between $1.7 billion and $1.8 billion, a marked increase from its $1.41 billion showing last year.