Citi downgrades Facebook and Google, says ad market expectations are too bullish

The logo of Alphabet Inc's Google outside the company's office in Beijing, China, August 8, 2018.
Thomas Peter | Reuters

The growth trajectory for the online advertising market doesn't appear to be strong enough to drive more gains for two Big Tech stocks that rely heavily on that business, according to Citi.

Analyst Jason Bazinet downgraded Facebook and Google-parent Alphabet to neutral from buy, saying in a note to clients on Sunday night that investors and other analysts were overly bullish on the growth potential for the advertising market.