SAN FRANCISCO — An investor class action accusing Zynga executives of plotting to sell their stock before shares tumbled is too vague to move forward, a federal judge has ruled.

In a six-page order issued Tuesday, U.S. District Judge Jeffrey White granted Zynga’s motion to dismiss In re Zynga Inc. Securities Litigation, 12-04007. Represented by Berman DeValerio and Newman Ferrara, plaintiffs claimed that Zynga executives touted the company’s health before and after its 2011 IPO, only to sell their own shares before the stock collapsed. White ordered the plaintiffs to revise their claims to include more specifics.