Could Options Activity In 3D Systems Be Pointing To A Takeover? By: Benzinga via Benzinga May 08, 2015 at 08:59 AM EDT With recent news that Yelp Inc (NYSE: YELP) and salesforce.com, inc. (NYSE: CRM) were putting themselves up for sale, CNBC ... Read More >> Related Stocks: 3D Systems Corp Macy's Salesforce Yelp Inc