In 2009 investment vehicle Elevation Partners, in which he has a share, bought between 1 and 2 percent of the social network. Following last week’s initial public offering that valued the company at more than $100 billion, it was reported that Elevation’s stake would be worth near $1.5 billion.

On the day before the May 18 offering, the New Musical Express and the financial pages of some of the UK’s leading tabloids said the launch would see Bono overtake Paul McCartney as the world’s richest rock star.

Sir Paul’s in the top spot with a wealth estimated to be as much as $700 million.

Although Elevation may have seen a spike in the value of its holdings thanks to the IPO, Facebook’s share price quickly fell nearly 25 percent from its opening price of $38. Frustrated investors have fired back, claiming lead IPO underwriter Morgan Stanley had divulged to select clients that its analyst had downgraded revenue estimates for the company in the days leading up to stock offering.

Any profit would also not go to Bono alone, as the U2 singer is one of nine partners in Elevation.

“Contrary to reports, I’m not a billionaire or going to be richer than any Beatle – and not just in the sense of money, by the way. The Beatles are untouchable,” the Irish superstar told the Daily Mirror. “Those billionaire reports are a joke.”

Any investment in the social networking giant is likely in for rollercoaster ups and downs.

“The real value of Facebook is not likely to be known until the hype of the IPO has died away and investors have been able to digest how the company is going to evolve to be the money making machine many expect it to be,” says Alpari UK chief market analyst James Hughes.