Kylie Jenner

Star Kylie Jenner wiped $1.3bn (£1bn) off the stock market value of Snapchat after tweeting that she no longer used its messaging app.Celebrity Kim Kardashian's half-sister posted: "sooo does anyone else not open Snapchat anymore? Or is it just me... ugh this is so sad."Snapchat's share price sank after Ms Jenner's tweet about its re-design to her 24.5 million Twitter followers.One million people signed a petition demanding Snap roll back the change.After dropping almost 8%, shares in Snap closed 6% down on Wall Street, and are now back near the $17 price at which the shares were listed when the company floated on the stock market.Snapchat is facing intense competition from Facebook's Instagram - especially for celebrity users - and Ms Jenner's attack comes at a time when investors are already worried.Ms Jenner later tweeted a follow-up: "still love you tho snap... my first love".