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.

Anyone watching the stock market yesterday saw, proverbially speaking, what spectators see at a bullfight: lots of blood and ultimately the death of the aforementioned bull. Unlike bullfights, the majestic bull was given new life today, as investors decided yesterday's 2.3% sell-off was overblown. Two stocks advanced for every one that declined on Tuesday, and the S&P 500 Index (^GSPC 0.87%) added 13 points, or 0.8%, to end at 1,755. 

While Wall Street reminded the matador not to forget his silly costume on the way out today, shareholders of the Irish manufacturing company Eaton (ETN 1.67%) still lost some blood, as shares shed 2.3% in trade. While Eaton actually beat quarterly earnings estimates, a cynical analysis of the results reveals the earnings strength was due exclusively to a one-time tax benefit. Margins and sales failed to impress, while earnings guidance for 2014 was also more conservative than desired. Today is just another example of the ancient nonsensical Wall Street adage, "if Eaton's beatin', ya needn't keep 'em," in play. 

Despite a mostly upbeat attitude in the markets today, shares of Seagate Technology (STX) felt none of the love, and investors sold off to the tune of 2.2%. The tech sector was a major underperformer today, slumping 1.7%, so truthfully Seagate Technology's weakness on Tuesday isn't anything to lose sleep over. Data storage is an area that should continue to grow at a healthy pace for the near future, so the market for Seagate's product isn't going anywhere anytime soon. What investors should watch carefully is the company's market share, since there's a ton of competition in this space and success depends largely on R&D budgets, innovation, and customer retention.

What a seamless transition this is to the day's final notable S&P 500 laggard, Coach (TPR -0.76%)! Shares of the high-end fashion retailer slumped 1.9% today, largely because customer retention is something Coach hasn't excelled at recently. In fact, bitter rival Michael Kors wowed Wall Street with a blowout quarter today – a quarter that reminded Coach investors just what they were missing. The same-store sales metric is one of retail's most watched numbers, because it compares apples to apples by measuring sales growth at stores that have been open at least 12 months. Coach was an abject failure in this department last quarter, while Michael Kors seems to be having no problem growing same-store sales healthily.