For BTC, I would say it depends on how you see the end goal of what bitcoin price is going to be. If you feel that the highest price it would get within the short period that you can wait is $10000, then I won't advise you to buy but  if on the otherhand you see the current price climbing to $15000 and above, then its the right time to hop in without looking back. It boils down to how you see things and you want to act on it.

For the stock part, because most stocks are not a global scale or the same conditions, its going to be really difficult to determine whether its the time to buy some or wait.