Kylie Jenner tweets, Snapchat nosedives

One tweet from US reality star Kyle Jenner was all it took for Snapchat to lose AUS$2.17 billion of its stock price.

Kylie Jenner later tweeted that she still loves the Snapchat app. (AAP)

A single tweet from US reality TV star Kylie Jenner about Snapchat has triggered a massive plunge in the messaging application's stock price.

Jenner, the half-sister of Kim Kardashian, tweeted: "Sooo does anyone else not open Snapchat anymore? Or is it just me... ugh this is so sad."

Wall Street panicked in response to the message, and Snapchat shares slipped almost 8 per cent at one point, totalling around US$1.7 billion (AUS$2.17 billion) in value.

They closed down 6 per cent.

Jenner later tweeted again: "Still love you tho snap ... my first love."