Short interest in 3D Systems Corp. (NYSE: DDD) fell by 8.1% to 20.87 million shares. Some 19.3% of the company's float was short. Days to cover fell from 13 to seven. In the two-week short interest period, the share price fell by about 13.1%. The stock's 52-week range is $11.01 to $19.76, and shares closed at $14.46 on Thursday, down about 0.6% on the day.