Manchester United fans have protested in recent years against the American Glazer family, who bought the club in 2005, due to the team's struggles on the pitch.
has said he is not going to buy Manchester United, after earlier tweeting that he wanted to take over the Premier League club.
boss, who has a history of making irreverent tweets, tweeted on Wednesday: "I'm buying Manchester United ur welcome."
But when asked on Twitter if he was serious he replied: "No, this is a long-running joke on Twitter. I'm not buying any sports teams."
Musk's initial tweet would have caused a frisson of excitement amongst United fans.
It also boosted the club's shares by nearly 17% to $14.90 (£12.31) in the US pre-market trade, before settling at $13.20 (£10.90) - showing the impact the billionaire has on his Twitter account.
Many have protested in recent years against the American Glazer family, who bought the club in 2005, due to the team's struggles on the pitch.
The anti-Glazer movement gained momentum last year after United were involved in a failed attempt to form a breakaway European Super League.
Manchester United have been champions of England a record 20 times and have won the European Cup, the most prestigious club competition in the global game, three times.
But disquiet among fans as to how the club has been run has been exacerbated by the team's poor start to this season, losing the first two games including last Saturday's 4-0 humiliation by Brentford.
As of Tuesday's close, the football club had a market capitalisation of $2.08bn.