The Dow Jones Industrial Average (DJINDICES:^DJI) gained 38 points in pre-market trading, suggesting a positive start to the stock market today. Investors can expect more stock swings, particularly as dozens of companies post first-quarter earnings results throughout the day. Meanwhile, the Federal Reserve begins its two-day monetary policy meeting today and is widely expected to again scale back its bond-buying economic stimulus measures. 

Stocks on the move this morning include 3D Systems (NYSE:DDD) and Merck (NYSE:MRK), which both posted earnings results before the opening bell.

Image source: 3D Systems.

3D Systems met Wall Street's sales and profit expectations for the first quarter, booking a 45% boost in revenue and earnings of $0.15 a share. Organic growth, a critical metric for the 3-D printing company, fell to 28% from the 34.3% rate set a quarter before. Printer sales outpaced materials sales, leading to a drop in profitability. But the company seems to be seeing strong demand across multiple product lines. In fact, 3D Systems couldn't make enough direct metal printers to fill its orders and was forced to end the quarter with a hefty backlog.

CEO Avi Reichental addressed the company's ramped-up spending in areas such as acquisitions and research and development, saying in a press release that those investments "continue to pressure our quarterly results" but should "set the stage to substantially compress the time required to deliver greater value." 3D Systems said that profitability should improve starting next year. The company forecast full-year sales of $700 million, almost 40% above 2013's results and roughly on par with analysts' projections. 3D Systems' stock was down 6% in pre-market trading. 

Merck said today that its first-quarter sales fell by 4% to $10.3 billion. Analysts had been looking for a more modest 2% decline. As expected, the drug giant's results were hurt by expiring patents, including a 20% revenue drop for the blockbuster asthma treatment Singulair after losing exclusivity in major European markets this past year. Merck did manage to beat profit expectations, though, booking $0.88 a share in earnings. That was an improvement over last year's $0.85 result, and better than Wall Street's target of $0.79. CEO Kenneth Frazier said in a press release that "discipline in managing our costs" was the driver behind the surprising profit improvement. For example, Merck cut $200 million out of its marketing and administrative expenses in the quarter. But the company also sliced $400 million from research and development spending, walking a fine line between cost cuts and underinvestment in its future drug portfolio. The stock was up 1% in pre-market trading.