Down go the markets on renewed fears over an end to quantitative easing. The Dow Jones Industrial Average (DJINDICES:^DJI) has fallen sharply, diving 120 points, or 0.78%, as of 2:25 p.m. EDT. Most stocks are in the red, but today's dip is a reminder that easing has to end sometime -- although Wall Street has yet to accept that truth. Here are the stories you need to know about on the Dow's down day.

Volatility takes the day
The CBOE Volatility Index (VOLATILITYINDICES:^VIX), or the market's "fear gauge," has shot up 5.4% today as part of a nearly 27% run-up over the past month. While Federal Reserve chairman Ben Bernanke has warned that slowing quantitative easing could slow down the economy's recovery, investors shouldn't panic over a draw-down of bond-buying. The Fed can't keep up stimulus forever, and while easing has helped some sectors of the economy regain their footing, eventually "QE infinity" will have to come to end. Prepare for more volatility ahead as Wall Street comes to grips with that eventuality, but don't panic and divert from long-term goals. The central bank won't jerk stimulus out from under the feet of the economy, but rather taper it off over time. That's nothing to fear.

Those knee-jerk sentiments from Wall Street have sent Home Depot (NYSE:HD) shares plummeting 2.6% today. No doubt stimulus has played a part in housing's rebound from its recession lows, but Home Depot has performed well for investors lately. The company's standout first-quarter earnings and optimistic outlook for full-year profit are good signs for this stock's future, and so long as housing continues to tick up, there's no reason to doubt Home Depot now.

IBM (NYSE:IBM) shares have also fallen to the bottom of the Dow today, down 1.6%. The firm purchased cloud-computing company SoftLayer today in what is reportedly a $2 billion deal. Cloud computing has taken off recently, and IBM's purchase should further cement Big Blue as a key player in this growing industry. Amazon has already thrived on the back of the cloud-computing industry by offering public clouds to smaller and midsized businesses, but IBM could use its own public clouds to offer its services to corporate customers.

Fortunately, a few Dow members are beating the pack today, and Merck (NYSE:MRK) leads the index with a 2.9% gain. The firm's melanoma drug lambrolizumab posted strong clinical data at the American Society of Clinical Oncology this past weekend, reducing the growth of tumors in late-stage melanoma patients by 38%. Merck has struggled with falling sales as a result of patent expirations -- particularly on its top-selling therapy, Singulair -- and if lambrolizumab can pass regulatory hurdles and live up to its blockbuster expectations, the drug will go a long way toward firming up Merck's future.

Fool contributor Dan Carroll has no position in any stocks mentioned. The Motley Fool recommends Amazon.com and Home Depot. The Motley Fool owns shares of Amazon.com and International Business Machines. 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.