Today shares of 21Vianet Group have been on a rollercoaster, carried along by a short report from a relatively unknown firm21Vianet Group Inc ( VNET) has seen a lot of action these couple of days, and now we know why. On Tuesday, ValueWalk received tips from two trusted sources that someone was about to release a short thesis on the company. Now we have that report in hand, and it comes from a firm called Trinity Research Group. sign up for our free newsletter Tug o’ war with 21Vianet Group stock Our sources tell us that 21Vianet Group stock spiked earlier today due to some big-time options activity. Because of that action, many investors probably assumed that prominent short-selling firm Muddy Waters was about to release a short thesis on the company, as shares of WBAI did e as shares of WBAI did today. Shares slid by as much as 20%. Then when Trinity released its report today, investors realized that it wasn’t coming from Muddy Waters, so short-sellers—most likely Muddy Waters fans—probably moved to cover their positions. 21Vianet Group spiked by 15% because when Carson Block’s firm targets a company, its stock usually is negatively impacted, but the fact that the report comes from a relatively unknown firm worried investors less—until, that is, they had a closer look at the report. 21Vianet Group accused of fabricating results Trinity alleges after conducting a six-month investigation that 21Vianet Group is guilty of both accounting and securities fraud. The firm believes that the NASDAQ will eventually delist the company and that it has been reporting “fraudulent financials and operating metrics” since its initial public offering in 2011.