Long floated his company Parthus on Nasdaq in 2000. He raised 35m from selling shares before the market crashed. He eventually sold his remaining stake but at a fraction of the bubble valuations.
He is founder and managing partner of technology fund Atlantic Bridge Ventures, which has assets of over $500m and has raised cash from high rollers such as Denis O'Brien and Dermot Desmond. Last year, it launched a 140m fund for Irish technology companies with the potential to scale globally. Long spent about 7m buying Martin Birrane's huge Georgian mansion in Killiney. His wife Olivia Gaynor Long recently sold the Residence nightclub in Dublin to her brother Peter, according to reports. It had been loss-making. The Longs own a valuable property in Fontevielle Port in Monaco.