As we all know, (DeFi) is one of the aspects of liquidity that made bitcoin price jump from 15000 dollar to 30000 dollar easily and fast.
I'm not so sure we all know that--or perhaps I should just speak for myself. I didn't think DeFi had anything to do with bitcoin's meteoric rise, nor did I see any mention of DeFi in any of the discussions I read about that rapid increase. Most opinions I read (and I agree with this) were linking recent purchases by a handful of big institutional buyers like MicroStrategy and others to the price increase. That makes a lot more sense to me, because tons of buying usually leads to a higher price.Charles-Tim described it nicely, and everything that happens with DeFi is thanks to BTC, not the other way around. We see this best when the price of BTC starts to fall, mostly all followers go red, and then they need a lot more time to get back on track.
That sounds about right--and I honestly don't even fully understand what DeFi is all about other than offering brave investors a chance to make astounding returns. I have yet to hear how it's going to solve a real-world problem, and I've got my doubts about the whole thing. Maybe I just got too jaded after all those useless ICOs went bust. 
