I have bought my btc at 5000$ and i have sell around 40% of it at 17000$ which was a huge profit for me . Rest of the amount ill wait till the end of 2018 and will see how much growth it has make and sell accordingly . I don,t have a fixed price or value in mind at which i would want to sell but whenever i feel that the price has reached its peak for the year i sell a certain amount and keep the rest for next year and even buy some more of it when the price is low.