In some cases Stocks are sold because of Margin Calls. I am not sure if people could have borrowed funds to buy AGO but that is definitely could be the case for FMG etc. CFD/Warrants/Options are other reasons for selling.
Similar to GFC, I believe ASX/Government should stop short selling for at least 3 months and we will definitely, see a huge improvements in many SPs. Although ASX is making money from these instruments.
AGO Price at posting:
20.0¢ Sentiment: Buy Disclosure: Held