I don’t think it means it was bought by just one entity. It really just means the total qty of total traded qty which is held by the person. 81% is not that much high and pretty common if the price has fallen down on that day then there is high chance of people holding it till next day or until they see some profit. Sort of like BTST.
Check today’s data and you will find most of the stocks which went down or didn’t rise much are held for tomorrow or maybe longer.