Long was one of the brightest lights in Ireland's dotcom boom at the end of the 1990s, with his Parthus company floating on Nasdaq in 2000. Long (59) picked up €35m from selling shares. Then the market crashed. He eventually sold his remaining stake but at a fraction of the bubble valuations.
He spent about €7m buying Martin Birrane's huge Georgian mansion in Killiney, and re-invented himself as a super-shrewd tech investor. His AbVen fund has raised cash from the likes of Denis O'Brien and Dermot Desmond and has scored some big exits as well as buying stakes in smoking-hot tech firms like Movidius and Fieldaware.
Long's wife Olivia Gaynor Long owns Residence nightclub in Dublin. There were shopping centre interests in southern England during the boom, and the Longs own a valuable property in Fontevielle Port in Monaco.