a very classic words, buy cheap and sell high, I think it can not be identified with bitcoin alone, a natural thing in life. almost in every business we have, we always imagine a higher return from the capital we have. however, it is not easy. not everything we imagine come true, all through a long process.
one of the economic references, that buy when prices fall and start selling when you feel that you are getting a reasonable profit. of course this will be done by all components of society in trading, including in the field of crypto. bitcoin has now reached a high enough price but it is not maximal and the possibility of falling back could occur, don't hesitate to buy and invest because bitcoin will reach its peak next year.