Facebook eating Twitter's lunch: Wall Street

Chris Ratcliffe | Bloomberg | Getty Images

It's clear that Facebook is the most-popular social network. But Twitter is falling further and further behind the social king in so many areas that Wall Street is running out of reasons to recommend owning shares of the little blue bird.

The latest was Ken Sena of Evercore ISI, who on Thursday downgraded the stock to "hold," the Street's equivalent of a sell recommendation.

Here's why Wall Street hates Twitter.