Apollo Hospitals - how to analyze spike in volume?

Hello members,

I observed an unnatural spike in volume and price of Apollo Hospitals on 30th Nov 2017. While on regular days there’s volumes in multiples of hundred thousands, that day traded volume was 10x : 6.9 million. I can relate the price drop to high volume - the sell order would fill only with falling prices.

  1. Trying to reconcile sell
    There was no material news release around that time. There was a price rise along with higher than usual volume (1million) few days before this spike and few days after the Q2 earnings release (13th Nov) which I assume drove buyer interest. So the earnings report could not have initiated the large 6 million sell off?

  2. Trying to reconcile demand
    Where would the seller(s) have found 10x demand on that day? Or I could be missing something on how exchanges work to fulfill large sell orders.