You mean just like all speculation in the financial industry? Just slap a fancy logo and business on it and it's all perfectly above board? The notion that capitalism and free markets are great when giant banks are involved but not when individuals are is strange to me.
Can we please dispense with this notion that there is some comparison to be made in this way between crypto currencies and stock market trading. Stock markets are and have been an essential part of the system we live in. By allowing many people/ organisations to invest in a company via shares stock markets have enabled many great things to be achieved that would not have been possible without this method by which a company can raise money to invest. Stock market investing (at least in some cases) offers the ability to invest in companies that provide goods and services that actually have some sort or genuine utility and improve the quality of life for people.
Crypto currenciesa on the other hand offer no such similar benefits. Sure I have read plenty of articles that speculate about possible uses and benefits of block chain technology but current crypto's are not currencies but speculative instruments with no meaningful utility which consume vast amounts of material and energy.