You might be right, but sometimes the "retracement" does not end up coming, and so maybe it is no BIG deal if you were already prepared for UP at the end of September when BTC prices were in the $26ks and $27ks, but then if you think about it, we have largely had Upwards BTC price moves and no significant and/or meaningful retracement, so far.. and whether such retracement comes or not is not exactly high odds. Maybe it is 50/50? And how BIG of a retracement would you like to see? 10% or more?.. 10% only gets you down into the $33ks .. so would that be good?
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.
What if there is no retracement to $39k? and the price of Bitcoin keeps on gaining, you might miss out on accumulating your Bitcoin because you are waiting for a retracement. I could suggest if you have enough money divide it into three parts that you will use to buy the Bitcoin dip, buy when the Bitcoin price is at peaks, and buy Bitcoin with the DCA strategy, instead of waiting for the Bitcoin price retracement and miss out on holding a Bitcoin. Just as @JayJuanGee mentioned to you if you are staying in BTC for 4-10 years it might end up doing you good because the BTC price will be above your buying price in those years.