[lottin]

The reason they require so much collateral is because the value of the collateral is highly correlated with the value of the investment, since both the investment and the collateral are in the form of crypto-assets, and crypto-asset prices tend to move together. This means, in the event of a crash in the crypto market, the probability of incurring losses from such a loan would not be negligible.

Then there's also foreign exchange risk. The return on these loans is quoted in terms of the currency the debt is denominated in, whereas what the investor cares about is the return of the investment in terms of their local currency. This is the same situation that an investor would face if they decided to buy Argentine bonds, which pay over 20% annually in pesos. The return that they would get in their local currency would likely be much smaller. It could even be negative.