I don't watch real close, but here's what I observed.
On Frankfurt exchange, the the HOD was 0.56 Euro, a 19% gain. By the end of the trading session, the price was down to 0.52, the 10% gain you found. The volume was pretty light, around 80,000 shares for the day. The jump to 0.56 occurred on a volume spike of about 30,000 shares.
That's what I saw. Maybe s40 can enlighten further.
Best Regards.