The best thing, according to me would be to sell 30 to 40% of your bitcoin and buy into other top 20 to 30 coins as per the largest market cap and hold on to them for the years to come.
You will be able to diversify and reduce your risks.
That strategy is good because as of right now the bitcoins price is going very high and it is still going up , and the higher it is the less people will be able to get their hands on so their best option is to switch the top altcoin that are close to bitcoin , because they will be easier to mine to get and the exchange rate will go higher the higher the price of bitcoin will.