By Dave Sebastian 



  Shares of the Chinese search-engine company Baidu Inc. and iQiyi Inc., the Netflix-like video-streaming company Baidu has a majority stake in, fell Friday after iQiyi said the U.S. Securities and Exchange Commission is investigating its books. 


  iQiyi shares fell almost 11% to $19.37, and Baidu shares fell 6.3% to $116.70. 


  On Thursday, iQiyi said the SEC had asked for financial and operating records from January 2018 onward, as well as documents tied to acquisitions and investments cited by the investment-research firm Wolfpack Research. 


  Baidu also reported a slight hit in revenue for the second quarter due to a decline in online advertising on iQiyi, though Baidu's profit rose. 


  Write to Dave Sebastian at dave.sebastian@wsj.com