Dick Costolo

Twitter will lay off employees next week as freshly-returned chief Jack Dorsey pushes for a leaner operation…

Some 13 million people signed up to Twitter for the first time in the last three months, but the influx was not…

Twitter Inc revealed on Tuesday a tripling in quarterly losses as it prepares to list on the New York Stock…

Twitter Inc. plans to bolster security on its site after the account of the Associated Press news service was…