B. Riley Financial offices in Westwood. (Jason Armond / Los Angeles Times) Businessman Brian Kahn has pleaded guilty to conspiracy to commit securities fraud in a case that brought down a hedge fund, helped lead to the bankruptcy of a retailer and damaged West Los Angeles investment bank B. Riley Financial. Kahn, 52, admitted in a Trenton, N.J., federal court Wednesday to hiding trading losses that brought down Prophecy Asset Management in 2020. The Securities and Exchange Commission alleged the losses e ...