Shares of LinkedIn Corp, operator of the most popular social network for professionals, fell 20 percent in early trading on Friday, wiping out more than $6 billion of market value, after the company slashed its full-year forecast.

LinkedIn reported on Thursday its slowest quarterly revenue growth since it went public four years ago.

The surprisingly weak results followed Twitter Inc’s on Tuesday. Twitter’s stock fell by as much as 24 percent, slicing about $6 billion off its market value.

Social media companies are a bit to volatile for me.