The research firm has taken a short position in shares of Roblox and says the company is over-exaggerating its daily active users by possibly as much as 42%.
Amazon has been pulling back from using Just Walk Out in its own stores, including by removing it from dozens of its U.S. Amazon Fresh grocery stores this year.
Horowitz' prior support for Trump had prompted a backlash from certain influential Silicon Valley Democrats, such as ex Sequoia Capital leader Mike Moritz.