No matter the market, there will always be losers -- a few lagging disappointments holding back a Wall Street rally, or several big losers leading a bearish day. The S&P 500 (SNPINDEX:^GSPC) ended the day down almost 0.3%, but several notable big names helped to drive down the index and make investors pull their hair out in frustration. Here are the three worst stocks today that you need to know about – from chemicals to semiconductors, these stocks put a dent in Wall Street's Thursday.

Three's a disappointing crowd
Semiconductor maker Broadcom (NASDAQ:BRCM) couldn't shake the blues today, as shares fell 4.2% The company's adjusted earnings did manage to  beat analyst expectations when it reported on Tuesday – with an adjusted EPS figure of $0.76, and revenue of  more than $2 billion (at a 14% year-over-year increase) both topping expectations. Still, the company's prospects have been hurt by Apple's fall: Broadcom makes around  13% to 15% of its sales from Apple alone and, while Apple's earnings weren't all that bad, they've been enough to spook investors from both it and some of its suppliers.

Rival Qualcomm's (NASDAQ:QCOM) stellar earnings today  were also likely a factor in Broadcom's fall. Qualcomm, the leader in mobile chipmaking, beat estimates, and posted strong guidance today -- another sign to investors that Broadcom's toughest rival could be forging an even greater lead over its competitors.

Moving on to our second big loser today, Dow Chemical (NYSE:DOW) certainly didn't make shareholders happy, as its stock plunged nearly 7% on the day. The horrible drop put the kibosh on what had been a great start to the year: Prior to today, Dow had posted shares gaining just around 7% over the past month.

Unfortunately for investors, disappointing earnings slugged  Dow in the gut. Sales fell, but managed to top analyst projections; earnings per share, however, just failed to meet expectations. The overall numbers weren't actually all that horrible, but weakness out of China and Europe sent shareholders into a selling frenzy.

Finally, our third big loser of the day is Time Warner Cable (NYSE:TWC), as shares plummeted a nauseating 11.3% today. Time Warner reported earnings today, but it was poor guidance  that sent the stock dropping to its lowest point since November. The company reported that operating margins in 2013 could fall by 0.5% to 1% based on higher programming costs, and with cable television subscribers falling across the country -- Time Warner alone lost 129,000 cable tv customers for the quarter -- the company's prospects look gloomy, at best.

Mobile keeps on rising

Fool contributor Dan Carroll has no position in any stocks mentioned. The Motley Fool recommends Apple. The Motley Fool owns shares of Apple and Qualcomm. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.