A day after going on about how remarkable the bullish run in the S&P 500 Index (SNPINDEX:^GSPC) had been in 2013, I come face to face with a day like this: a day where the index plummets from the euphoric five-year highs of yesterday to log the worst day of trading since November. Such a slap in the face makes for an apt preface to today's rundown of the three worst stocks in the S&P -- companies that clearly did not live up to the expectations of yesterday. 

A fine example of a company that failed to meet expectations was Garmin (NASDAQ:GRMN), whose shares tumbled 9.4% today after underwhelming revenue and profit estimates for the coming year turned investors off from the navigation device company. The concept of buying an entirely separate product that performs a limited range of GPS services is becoming outdated as more and more mobile technologies can perform the same function. 

Rig contractor Nabors Industries (NYSE:NBR) also took an ugly fall Wednesday, dropping 7.4% on news of a lower-margin environment hit the wires. Operating on a contractual basis, stock in Nabors is subject to rapid price swings, determined largely by the fees it can charge to rent out its drilling rigs. With rates sliding by nearly $1,000 a day in the contiguous U.S., investors were keen to avoid shares today, selling off heavily.

Lastly, office supplies company Staples (NASDAQ:SPLS) shed 7.2% after rival retail outlets Office Depot and OfficeMax agreed to terms on a merger. Staples shares, which surged 13% yesterday on rumors that its two massive rivals would combine forces, oddly sold off today on confirmation that those rumors were true. It's as if the market said, "Whoa, we were a little too enthusiastic yesterday. This thing isn't as great as we thought it was."

Fool contributor John Divine has no position in any stocks mentioned. You can follow him on Twitter @divinebizkid and on Motley Fool CAPS @TMFDivine.

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