Twitter’s stock has fallen to an all-time low amid rumours it is about to allow users to post tweets as long as 10,000 characters.
The dip happened after technology news website Re/code reported that the current 140-character tweet limit would be abolished.
The feature is rumoured to be launching at the end of the first quarter, however an official announcement has not been made.
In a series of tweets, Twitter co-founder and chief executive Jack Dorsey called the 140-character limit “a beautiful constraint.”
But he said the company had seen more people sharing screenshots of text – a way to get around the limit.
He said: “We’re not going to be shy about building more utility and power into Twitter for people.
“As long as it’s consistent with what people want to do, we’re going to explore it.”
The feature is likely to allow tweets to expand to reveal more content when users click on the tweet.
Twitter has been experimenting under Mr Dorsey to make the service more engaging.
It recently introduced the Moments feature, added polls to tweets, rolled out a buy button and replaced its star-shaped favourite icon with a heart-shaped icon called like.
Twitter’s share price now stands at $21, down from a peak of $69 in January 2014.
It had its slowest user growth in 2015 – and its user numbers were eclipsed by photo-sharing app Instagram, owned by Facebook.