It's also taking a hefty charge related to its March acquisition of mobile game company OMGPop.
Zynga Inc. said late Thursday that it expects to post a loss for the third quarter, largely because of the $85 million to $95 million charge on the OMGPop purchase.
It bought the company behind "Draw Something" for $183 million.
Baird analyst Colin Sebastian says Zynga's transition from Web-based Facebook games to mobile is "more painful than expected."
Zynga's stock is down 19.3 per cent at $2.27 in late morning trading. It hit an all-time low of $2.21 earlier. The San Francisco company went public Dec. 16.