I do not think we can get a huge profit in just over 3 years, compared with a mutual fund that takes at least 10 years to get 200% profit or gold that takes more than 25 years to get 100% profit.
even just within 1 year bitcoin has increased more than 600%. I remember when earlier in the year of 2017 bitcoin is still around $1000 and this time around $6000 even reached ATH $7500. so it's really been proven, bitcoin very profitable for the long term even short-term.
Yes I agree with you and it work as well because thats what Im doing here from a long time when the price go down then I start to buy bitcoin and I buy bitcoin as much as I can and then I keep it on hold for a long time and then Im waiting for a right time when the price go high then I sell all my bitcoins and take a very good profit from it.