For me I think there's is no best time to sell Bitcoin investment. Because what ever movement that Bitcoin is making now is not really a new thing, it have been there is the creation of Bitcoin. The rising and falling of Bitcoin price is just to provide investors the opportunity to either by or sell.
Anytime can be a good time or bad time to sell your Bitcoin, because the price will always rise and fall. The time you sell your Bitcoin depends on your investment target.
I think the best time to sell Bitcoin depends on individual basis because we got it in different time, so selling it will be in different time which is why I said it is based on individuals intension. Selling of Bitcoin can never be in a row, meaning, for us to sell Bitcoin within a specific time Is not possible because many people that failed to use the opportunity they got from beginning are now struggling to have it even though it is at all time high, because they seriously believe in it that bitcoin price doesn't have limitation and that is how it's going to be, it will look continue to rise and rise and rise because it is getting value every day.