You are inferring too much from that comment. I think those people just had large stock holdings in general and were he market went up a lot that day.

The market briefly went up 7% that day.

To make 2.5 billion just from holdings they must have had stock holdings of 35 billion. Then the next day they lost a lot more than that. I doubt it very, very much.

There is a difference between making 2.5 billion because you owned stocks and the market went up and making 2.5 billion because you bought just before the market went up and then you sold.

It's unlikely you can make 2.5 billion with a single unleveraged trade. The market went up by what, 6-7% that day? Nobody bets his whole net worth on this to make a profit like that. So I think leverage was definitely involved, which just shows that insider info was definitely there.