Albert Einstein, when creating first the special and then the general theory of relativity, did use lots of thought experiments. A thought experiment is a metaphor, an explanation to reach understanding by analogy — like, for example, what happens if we sit and ride on a light beam.This article uses also thought experiments designed to provide analogy and bring clarity in a time of euphoria of a bull crypto-market.It may have been almost 2 years ago when I did answer a question on Quora — ‘What is the most dangerous crypto-currency.’ At that time, as well as now, my answer is the same — it is the group of so-called ‘stable’ coins.While there are a wide variety of ‘stable’ coins, I can divide them into 2 groups:- derived from fiat currency: like for ex. USDT / Tether and USDC / Circle — receiving fiat USD and giving a crypto-coin which promises its worth is 1 USD- derived from a major crypto coin: like DAI — receiving Ethereum and giving a crypto-coin which promises its worth is 1 USD, based on the ETH-USD exchange rate at the time of purchase.Please note that I use the verb ‘promise’. The majority of crypto-traders and crypto-investors are certain that the peg (the 1:1 exchange rate) is guaranteed.But, is it?!After receiving the fiat currency and giving the crypto trader/investor (fiat-based) stable coins, the crypto-exchange or the ‘stable’ coin issuer can consider the fiat that was received to be earnings — to be spent and consumed.A decent exchange/issuer, on the other hand, treats the fiat received not as an earning but as savings — to be returned back when demanded.The first example is of a fraudulent exchange or coin issuer. But let’s consider the stable coins obtained from an issuer that I consider to be decent…