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.
You can't say ''what if there is no retracement'', because surely there will always be retracement. Following the law of economics when supply exceeds demand there is bound to be retracement. Because there more willing sellers than willing buyers and even @JayJuanGee knows this. Bitcoin is not a stablecoin and saying what if there is no retracement doesn't go well. Yes DCA strategy is very good and I'm not disputing that fact, but what I am saying is I don't accumulate bitcoin due to FOMO because of the knowledge I have gathered on bitcoin investment even though my forum accounts says otherwise. Yes I am into bitcoin as as a long term hodler and I am not disputing the fact that we are yet to see the full potentials in bitcoin investment. So since am going to be around and holding for a long term what's the rush of always buying the top. I feel more comfortable buying when there is a 5 to 10% dip in price from high of the week or month.