City Gourmets, operator of Madisons coffee bars, saw its shares plunge in value by one-third on its first day of trading on the Alternative Investment Market (AIM).
But the shares, placed at 100p, eventually rallied to 781/2p - valuing the company at £16.4m.
The coffee chain recently amalgamated with Lanica, an investment vehicle used by businessman Andrew Regan last year to launch his failed £1.2b bid for the Co-op.
A spokesman for City Gourmets described the first day problems as the "last aftertaste" of Lanica Trust's chequered past.
Hundreds of disgruntled shareholders were "looking for their first opportunity to exit from Lanica", he added.
"They had lost a lot of money and wanted to cut their loses and get out. We will have a far more accurate picture in three months' time when the people still with shares will have them because they want them," said the spokesman.