Shares in Twitter jumped more than 20% after a report said the home of the 140-character tweet had received takeover approaches.
Twitter, which has been the subject of takeover rumours before, is getting closer to a sale, according to the US business news channel CNBC.
Potential suitors include Google and Salesforce.com, the report said.
Twitter's board of directors is open to a deal, which could come by the end of the year, according to CNBC.
Last month Twitter shares jumped after comments from co-founder Ev Williams.
When asked on Bloomberg TV whether the company could remain independent he replied: "We're in a strong position now, and as a board member we have to consider the right options."
The $26bn purchase of the social network LinkedIn by Microsoft has helped to stoke speculation about the future of Twitter.
The company's flagging performance has also spurred talk of a takeover.
Twitter has never made a profit and sales growth has been slowing in recent quarters.
In July, Twitter reported that second quarter sales had risen almost 20%, the weakest growth since its stock market flotation in 2013.
'Lost its way'
Co-founder Jack Dorsey took over as chief executive in July of last year after the previous boss, Dick Costolo stepped down.
Mr Costolo, who had been chief executive from 2010, was under pressure from investors unhappy with the firm's performance.
In May Mr Dorsey told the BBC that "we're making progress" but "things take time to change."
But analysts wonder if Mr Dorsey is distracted by his payment firm, Square.
"With ex-CEO Dick Costolo lacking ideas and founder Jack Dorsey split between Twitter and his other company Square, the social network has lost its way," said Jasper Lawler, an analyst at CMC Markets.
"The hope for investors would be that under the wing of a big company, it could expand its user base and better monetise those users," he added.
Twitter shares added 21% on Friday to close at $22.62.