That's the hack tokens right?
I don't know what the procedures are but the hacker was able to send the tokens to IDEX.
55 million tokens is not that big IMO, personally I own millions of tokens and it does not value a lot for me with the current price.
Agreed with you that is not a big transaction so many people have big amount into their wallet I also have very decent amount for staking purpose to keep collecting monthly airdrop. I don't think that is some kind of hack attempt or suspicious transaction to get worried.