I would hold part of it, but I should also invest. There are currently, in the cryptocurrency market, projects related to blockchain as a service and blockchain applications, with potential to grow in the long-term and that I think worth some investment.
Holding is nice idea and part of earning bitcoin but you should invest that while waiting to increase the price of bitcoin and you can use trading also and do not depends on the investment where you could lose your money with investment .
Investing it into questionable investment is risky you have the more risk you are taking rather than the result you are anticipating. My advise for you is that You hold all of it until the price of Bitcoin one day get comfortable for you to sell, you may need not to worry about the price going down now as it is steady as of the moment.