RBCCapital downgraded TwitterInc. to underperform from sector perform after the research firmconducted a survey of advertisers, TheFly.com reported Sept. 23.

RBC analystMark Mahaney noted that the company's value to advertisers could be declining.Mahaney added that out of all the ad professionals surveyed, 30% do not do anybusiness with the social media platform, with 28% planning to lessen theirspending on Twitter.

Theanalyst also lowered the price target range for the company's stock to $14 from$17.