When we get to a new high that has not been recorded for long time, like we moved from $33k to 38k I would wait for a retracement in the region of $35k before I add to my holding. But if we don't get back to $35k and move from $38k to $42k I would wait for retracement in the region of $39k It has been a strategy I have been using for long and it has been helpful to me. You know we cannot rule out a possible retracement. What I don't like is buy the top of the month.
You shouldn't always anticipate for a retracement before you buy Bitcoins. You can buy when you have enough spare money. The market sometimes cannot be predicted so the more time you spend waiting for a retracement you might actually be missing out on the profits you would have be earning from your investment. So, if you really want to acquire enough Bitcoin in the up coming years, you might want to consider using different strategies when it comes to accumulating Bitcoins. There's no one method of accumulation, you use what ever method best suits the current condition of the market.