Shares of Medidata Solutions Inc (NASDAQ:MDSO) tumbled Tuesday after the software-as-a-service developer reported Q1 earnings and revenue trailing analyst expectations. Medidata Solutions Inc (NASDAQ:MDSO) stock performance was -22.74% in last session and finished the day at $40.71. Traded volume was 10.52million shares in the last session and the average volume of the stock remained 763.52K shares. The beta of the stock remained 0.65. Medidata Solutions Inc (NASDAQ:MDSO) insider ownership is 4.90%.

Trade-Ideas LLC identified Abraxas Petroleum Corporation (NASDAQ:AXAS) as a “perilous reversal” (up big yesterday but down big today) candidate. TheStreet Quant Ratings rates Abraxas Petroleum Corporation as a buy. Abraxas Petroleum Corp. (NASDAQ:AXAS) dropped -8.39 percent to $5.03 Tuesday on volume of 6.58million shares. The intra-day range of the stock was $4.91 to $5.67. Abraxas Petroleum Corp. (NASDAQ:AXAS) has a market capitalization of $466.52million.

Cantor Fitzgerald is defending Unilife Corp (NASDAQ:UNIS) following a negative blog post made Tuesday. Analyst Jeremy Feffer noted that the article brings nothing new to the table. The analyst commented, At the heart of the author’s argument is the existence of “law enforcement investigations,” which we believe refers to an ongoing SEC investigation. We note that this investigation is more than a year old and was already public knowledge when Unilife Corp (NASDAQ:UNIS) signed long-term supply agreements with Sanofi, Hikma, Astra-Zeneca, and Novartis and when it recently reached a debt financing agreement with OrbiMed. Unilife Corp (NASDAQ:UNIS)’s stock on Apr 22, 2014 reported a decrease of -10.89% to the closing price of $3.19. Its fifty two weeks range is $1.80 -$5.80. The total market capitalization recorded $327.46million. The overall volume in the last trading session was 5.07million shares. In its share capital, UNIS has 102.66million outstanding shares.

Arotech Corporation (NASDAQ:ARTX) provides security & defense products. It recently announced that it had acquired UEC Electronic. The company hopes that it will integrate this business into its battery & power division. Arotech Corporation (NASDAQ:ARTX) announced that this deal to buy UEC involved an initial price of $28M to be met in cash, & common stock that amounts to around 0.78 million shares. On Tuesday, shares of Arotech Corporation (NASDAQ:ARTX) dropped -16.82% to close the day at $3.71. Company return on investment (ROI) is 5.00% and its monthly performance is recorded as -12.09%. Arotech Corporation (NASDAQ:ARTX) quarterly revenue growth is 16.67%.