Quote from: yefi on June 08, 2019, 06:15:14 PM

Quote from: PrimeNumber7 on June 08, 2019, 08:11:56 AM

Poloniex allows for 2.5x margin trading, which means the value of the margin longs, plus the value of the collateral was just under 35% of all Clam outstanding.

How are you calculating the 35%? Based on your assumptions, I'm doing: -1800 = (1939/8585)x - (2.5/3.5)x, which gives 3,685 BTC for the longs and collateral, or 43% of all CLAM.

The change in market cap was 6647 btc. I got this based on 3,625,200 outstanding, a high price of 0.00236825 btc, and a low price of 0.000535 btc. The high market cap was 8585 btc.

The 1800 BTC loss made up 20.96% of clams, if they were bought at the high. In other words, you could spend 1800 btc to buy 20.96% of clams outstanding at the high price. At 2.5x leverage, Poloniex's customers need to have collateral valued at 40% of margin loans outstanding, calculated by x = 1/2.5. 40% of 20.96 is 8.38, so an additional 8.38% of clams outstanding would need to be used as collateral for an 1800 BTC margin loan, bringing the total to 29.34% of clams.

I believe the above is actually how the margin system still works on Poloniex, and this actually results in traders being able to get 3.5x leverage, because they can use 1 BTC to buy 3.5 BTC worth of a position if the collateral is the same as the trading pair. I was able to replicate my mistake in saying that 35% of clams outstanding were used in margin loans plus collateral by incorrectly assuming a total of 2.5x leverage, or borrowing 1.5x the value of the clam collateral, or having equity of 60% of the margin loan.

Quote from: yefi on June 08, 2019, 06:15:14 PM

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The losses exceed the trading volume of Clam during the flash crash, so it is probably safe to assume not all positions were sold immidiately. If no Clams were sold, and their value was written down to zero, as few as 21% of Clams outsanding could have been in open positions. I would believe that Poloniex sold the open Clams positions they were unable to sell in the open market, probably at a fairly large discount.

You are right. 444 BTC of volume occurred in the first five minutes, but that only took the price down to 180K sat. There was less than 150 BTC down from there to 53K sat. That's not enough to account for a 1800 BTC loss. At most, it accounts for only 650 BTC.

The 30 minute tick with 444 BTC traded has a low price of 0.00175 BTC, which is at most ~253,000 clam, or ~6.9% of clam outstanding. The following two 30 minute ticks only have about 20 BTC traded in each tick, with a low of 0.00112 BTC, with a maximum traded of about 35.7k clam, or under 1% of clam outstanding.

Quote from: gentlemand on June 08, 2019, 12:15:52 PM

They should be picking up the bill.

Most exchanges that offer margin lending would cover losses in these types of situation. There is language in the TOS that says the lenders are taking the risk that borrowers will be unable to repay the margin loans, and lenders may not be repaid the full amount.

The reason exchanges will often cover losses is because if they do not, lenders will not want to use the platform to lend, which will lead to higher interest rates for borrowers, which will lead to lower trading volumes and lower profits for the exchange. I guess Poloniex thought the 1800 btc loss was not enough to justify keeping confidence in their lending platform. If they had the money, they could have bought the clam, and sold it over time at a higher price, and prevented the market from dumping from all the margin liquidations. I expect most lenders to stop using Poloniex to lend out their coins.