The U.S. Securities and Exchange Commission lost another insider trading case Friday—the agency’s second trial defeat in a week. The back-to-back losses have amplified concerns by some former SEC officials that it’s done a poor job picking its battles, but they also show the inherent challenges the agencies faces in these cases.

A federal jury in Santa Ana, Calif., returned a verdict that Manouchehr Moshayedi, the former CEO of the computer hardware company sTec Inc., didn’t sell company stock using insider information. Jurors also cleared Moshayedi on claims that he made false and misleading statements to investors. A Latham & Watkins team led by Patrick Gibbs represented by Moshayedi alongside co-counsel Thomas Zaccaro of Paul Hastings.