The momentum effect is that if the bitcoin price rises continuously over a week, it may keep growing for the next week. This is a common feature of almost all known asset classes, and we have found that the momentum effect strongly affects the cryptocurrency. We have designed a simple investment strategy in which investors buy Bitcoin only when their price increases by more than 20% from the previous week. This strategy has excellent returns and a very high Sharpe ratio. 
Firstly when you say we who are you referring to. This posts sounds like an advert well just like every advert claims to be the solution to every problem. We can't just go by mare words. The market is constantly changing what if there was a high of 20% then a low of 40% precedes it what then would you guys offer.
I don't mean to bring down you guys reputation but if you have facts you can go back and arrange the post with possible links