Forecasts from Twitter, flat user growth send stock diving

San Francisco

JACK Dorsey, the co-founder and newly returned chief executive of Twitter, seems to be quite adept at scaring investors.

On Tuesday, Twitter gave a dismal forecast for its fourth-quarter revenue and profits. Shares in Twitter, a social media company, plunged as much as 13 per cent in after-hours trading as Mr Dorsey and his lieutenants offered little explanation for the gloom in a conference call with investors. In a similar call three months ago, Mr Dorsey's pointed critique of Twitter's product failings sent the stock down 11 per cent.

The new projections, delivered as the company exceeded analysts' expectations for its third-quarter results, provided fresh evidence that Twitter i…