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Short interest during the two-week period ending September 15 fell on half of the four 3D printing stocks we follow. The sector is still digesting General Electric Co.’s (NYSE: GE) acquisition of two 3D printing firms earlier this month. Based on short interest, the acquisitions were a mixed, but slightly negative, a blessing for the major players in the 3D printing business.

Short interest in 3D Systems Corp. (NYSE: DDD) fell by 0.4% to 26.33 million shares. Some 24.8% of the company’s float is short. Days to cover fell from 10 to nine. In the two-week period to September 15, the share price rose by about 0.6%. The stock’s 52-week range is $6.00 to $19.76, and shares closed at $16.86 on Monday, up about 2.8% on the day.

Stratasys Ltd. (NASDAQ: SSYS) saw short interest jump by 17.3% in the first two weeks of September to about 6.96 million shares, or 14.3% of the company’s float. Days to cover remained unchanged at seven. The share price dropped 3.3% in the two-week period, and the stock closed at $22.96 on Monday, up more than 4% on the day, in a 52-week range of $14.48 to $32.52.

Short interest in The ExOne Co. (NASDAQ: XONE) rose by 2.3% to 1.75 million shares. About 18.7% of the company’s shares were short. ExOne’s share price fell about 2.6% in the two-week period. The stock’s 52-week range is $6.50 to $14.91, and the high was posted Monday. Shares closed at $14.53, up 2.8% for the day. Days to cover slipped from 15 to 14.

Short interest in Voxeljet A.G. (NYSE: VJET) increased by 7.9% to 604,995 American depositary shares, with days to cover dipping from nine to eight. The share price rose by about 6.4% in the two-week period to September 15. The stock closed at $4.55 on Monday in New York, up about 1.3% for the day, in a 52-week range of $3.50 to $6.99.