Bounty: Who lost money in the Defi Hack?

in #defi5 years ago

Something interesting happened today that has been described a bunch like here:

https://www.trustnodes.com/2020/02/15/hacker-makes-360000-eth-from-a-flash-loan-single-transaction-involving-fulcrum-compound-dydx-and-uniswap

Someone made about 350k shorting and crashing the market without financial risk, because they were able to borrow the money in a flash borrow, which means they did not need collateral.

What is not described in all these descriptions is how the money was made or who lost it.

If the profit comes from the short alone, does this mean the attacker just wiped the entire order book and margin called every long?

What exactly happened. Who was the money stolen from.

I‘d appreciate an explanation.

Sort:  

It's indeed not easy to understand because a flash loan must be paid back in the same transaction as far as I understood.

What was done:

  • lend (up to 10.000) ETH
  • sell on one exchange where the price is high
  • buy on another exchange where the price is low
  • pay back the (up to 10.000) ETH
  • keep the profit of the price difference on the two exchanges.

So the profit simply came from the price difference of two exchanges and actually nobody was really hurt - except that the people selling on the low-price exchange could have made more money if they had sold their ETH on another exchange. But that was their own choice.

But all this in one transaction - hmmmmm

STEEM ON!!!

This cannot be right. They shorted the market. Then must have closed the short. But in order for the other side to take that price people must have gotten liquidated.

Else i don't see how this works.

Ah - ok. Thanks for clarifying.
Makes indeed more sense.

Yes, that part doesn’t seem to be explained.
Also, the official statement says no user lost any money (zero losses). That can't be true, can it?

Right this is what is confusing me.

The loans cannot be affected....

Hi, @knircky!

You just got a 3.48% upvote from SteemPlus!
To get higher upvotes, earn more SteemPlus Points (SPP). On your Steemit wallet, check your SPP balance and click on "How to earn SPP?" to find out all the ways to earn.
If you're not using SteemPlus yet, please check our last posts in here to see the many ways in which SteemPlus can improve your Steem experience on Steemit and Busy.

I think You'll find This Post by @kingscrown gives some explanation on how he did it.

Cheers!

Thanks.

I still don't get how the money was made. It seems to be implies that the money comes from going short. That means someone must have been long and margin called, but this fact is never mentioned, hence this post.

@knircky has set 10.000 STEEM bounty on this post!
logo_for-light-bg_1000.png

Bounties let you earn rewards without the need for Steem Power. Go here to learn how bounties work.

Earn the bounty by commenting what you think the bounty creator wants to know from you.

Find more bounties here and become a bounty hunter.

Happy Rewards Hunting!

Congratulations to the following winner(s) of the bounty!

@knircky has added 10.000 STEEM of bounty on this post!

Coin Marketplace

STEEM 0.19
TRX 0.15
JST 0.029
BTC 63592.23
ETH 2551.58
USDT 1.00
SBD 2.75