You did not see the drop because the 90% drop is like a blip in the radar when compared to amazon future gains. Now imagine bitcoin's 2018 crash is amazon's 90% drop and you can see why it has the potential to appreciate a lot more. This also defeats your earlier tirade about how bitcoin is "unstable" and can never be used while stocks like amazon are stable except it wasn't stable till it became well known.
My data tells me bitcoin can appreciate a lot more than 20k. In fact it is poise to hit 1 million sooner than you think. I would estimate somewhere in 2027. 100k would be breached by 2021 (Disclaimer: This is if it follows its current trajectory, not financial advice) While it isn't "early early", its still relatively early to get your skin in the game while most people can still afford 1btc. Once it gets to $100k or even $20k, I don't see normies being able to afford a whole coin. Swings will also be less volatile once btc reaches $100k and beyond as institutional players get into the game. Governments and banks will be forced to hold some btc against their fiat which is rapidly losing in value.
As much as I hate to say it. Most things in life follows the 10/90 golden ratio. The ratio doesn't have to be exactly 10/90, but the basic principle is that the best few makes almost everything while the rest makes peanuts. This is prevalent in everywhere not only trading. The CEO makes millions, while the workers make min wage. The athlete who makes it to the big league makes millions. The youtubers with the most subs make $10mil++ a year. The most successful author JK Rowling is a bloody billionaire from writing books for christ sake, while most people will scoff at the idea of riches being an author. The Chads get 90% of the girls etc...
Future will have to proof that to be right. Instability for stocks is completelly different from instability of a currency. You mix up two entirely different things. "Unstable" in the case of bitcoin means that today you buy something at BTC $4,000 and next month you have to sell it at BTC $2,000. So that instability makes it impossible to use for financial transactions. That's why I compared it with these horrible currencies in a previous post. Nobody wants to do business with a "currency" that is as unstable as bitcoins. In these countries people refuse their own currencies and replace them by strong currencies: Iran rials Vietnam dongs Sao tome dobra Indonesia rupiah Belarus roubles Laos kips Guinea frans Zambian kwacha ... as they have the same problem as bitcoins. In no time you can lose all you have. You are never sure what you can buy with your bitcoin. People want stability for their hard earned money. And we don't need really bitcoins as with the existing currencies we can do all financial transactions we wish and we always know the real cost of it while bitcoins are more a lottery. To avoid that lottery all your income, expenses, investments... should be in bitcoins to neutralize the volatility of bitcoin price. Each switch from bitcoin to any other real currency would bring real financial risks.
Crypto is an asset class. Period. No different than equities, debts, artworks, antiques, precious metals, trading cards, musical instruments, real estate, or anything that has a perceived or real value. Asset value, real or perceived is elastic... it can go up, it can go down. Cryptos, but I'll specify BTC, in it's current incarnation, can not possibly become a replacement currency. It can however, be a medium of exchange between two or more parties that agree on it's value. Nothing more. Jack traded his cow for magic beans, Jack and the bean dealer agreed on the exchange. For better understanding, further research might begin with "scrip" and "depression scrip". The difficulty many have with such basic research on the subject is political, not economic. Currency is economics. BTC fails.
Any of the coins have significant value only if they are used widely. If I can step into any store and pay by some crypto, it has value. But this is so far from reality for now. Amazon's value is mostly the brand. You cannot create an instant copy of it, offer same quality service and expect to have the same customer base. On top of that, launching a coin seems to be extremely easy and can be done in weeks if not days. Try launching a global business with billions of revenue in days.
Bitcoin's value is in the brand. You can generate a clone coin but the network adoption (i.e. merchants, users others) won't be there. That is why most of the cryptocurrencies clones are worthless or worth much less. You cannot go to a store and pay with a gold bar, but I can assure, it has significant value. The value of anything, whether it be a share of Amazon or a pack of cigarette is exactly what another person/entity would pay for it given the time and location. A pack of cigarette has a higher value in the prison than in the outside world. Bitcoin's value according to the market is ~$4,000. It's not an opinion. If you have one, you can sell it for that much and if you don't have one, that's what it will cost you to acquire one. Other cryptocurrencies have their own market price.