Iona Technologies chairman and chief executive, Dr Chris Horn, is among those nursing hefty losses on paper following the sharp drop in global equity prices in the last few days. Dr Horn holds almost 2.37 million shares representing 12.4 per cent of Iona stock. However, this was worth a lot less yesterday than it was in July as the share price has fallen from $40 to just $22 by the time trade closed in Dublin yesterday. This cuts the value of Dr Horn's stake from $95 million to $52 million, a paper loss of $43 million.

Esat Telecom group is another share to have suffered during the recent downturn, putting a dent in the fortune of its chairman, Mr Denis O'Brien, who still owns 16.9 per cent of the company.

The share price stood at $27.875 on the Nasdaq as the Irish market was closing last night, having clawed back Monday's sharp 27 per cent drop. But the shares are down sharply on July's levels of $44.25, meaning Mr O'Brien's 3.1 million shares are worth $86 million on paper, some $51 million less than the $137 million they were valued at in July. Ryanair's high-flying chief executive, Mr Michael O'Leary, who retains more than 10 per cent of the airline's shares, will also have seen his personal wealth take a hit in recent days.

Ryanair's share price closed at 400p yesterday, a drop of 35 per cent from the high of 615p recorded in July.