One never can be 100% sure about the future and thus diversification is needed. So "going all in" can sound great now in theory, but it can come crashing down in your face worse than the scenario that you already gave. If you sold and bought some Bitcoin then you are in fine shape. I say do not cash out into fiat but keep it in the cyryptocurrency ecosystem. Bitcoin is the world reserve cryptocurrency so it is a beacon of relative stability in the wild wild west of the cyrpto-world. My latest article can be found here: https://steemit.com/steemit/@bitcoinmeister/video-from-january-where-i-recommend-that-twitter-incorporate-a-cryptocurrency-system-into-their-platform-and-where-i-describe