It was another day of mixed activity on Wall Street, as Veritone Inc. fell to its lowest level since July 2017. On the contrary, it was a good session for Nexstar, and for Viacom’s Class B shares. For AI-powered Veritone, the Closing Bell brought a sorry story for investors who rode on the company’s coattails through a meteoric autumn rise. By Sept. 1, Veritone shares were at $45.45, and seemingly headed well past $50. On Aug. 1, they were just at $15.56.