U2 frontman Bono and The Edge have doubled their money on an investment in cloud storage group Dropbox in just over two years.
The rock stars invested in Dropbox in October 2011 as part of a $250m (€184m) second round of fundraising, alongside Goldman Sachs, Benchmark, Greylock and RIT Capital. Existing investors Sequoia and Accel partners also ponied up in the funding round, which valued Dropbox at $4bn.
Last week Dropbox kicked off a $250m funding round, which is set to propel it towards an IPO. Valuations of the firm are now close to $8bn as investors seek to capitalise on demand for fast-growing internet stocks such as Twitter.
Bono, once described as the "worst investor" in America because of some shaky digital punts, has proved an exceptionally shrewd judge of emerging technology. He is a partner in venture capital group Elevation Partners, which has generated stunning returns off early stage stakes in the likes of Facebook and Yelp.