Well, I personally bought at 13k and then at 9k and then at 6k. You can never know the real bottom but if you believe in the long term and think Bitcoin will be for example 500,000 (just an example) then buying at 16k would be better than buying it at all time high but ultimately even if you bought at all time high you will still be good if you believe in it long term it's just that you won't maximize your position.