Shares of Twitter Inc (NYSE:TWTR) are currently down 7 percent on downgrade from Morgan Stanley. The social media site was downgrade to underweight from equalweight with a price target of $33 a share. Morgan cited increased competition for online ad revenue. For example, according to Morgan, advertisers are more likely to seek an ad place on Google Inc (NASDAQ:GOOG) or Facebook Inc (NASDAQ:FB) before Twitter. In addition, Morgan cited valuation concerns for the downgrade. The chart below from Morgan explains their valuation concerns: