To be honest, if someone has money to invest on the market then it's best to do a lump sum so that you won't have any emotional barrier upon doing that. Why I said that? It's because when someone is trying to invest on Bitcoin during the dips, the investor might feel that there's gonna be another fall and there will be some delay of investing due to the fact that it might fall lower again upon waiting.
Having fear if the price of bitcoin will go dip can even make one not to be able to use any of the strategies. No matter the strategy one chooses to buy bitcoin if there is fear of buying in the dip it can deprive one from buying bitcoin.
Yes, DCA is a good one but with that kind of money, and you know that it is the dip, you have the choice to buy it on the lumpsum for you to just spend that money away to the market and you only have to think about waiting.
All strategies are good to invest bitcoin but investors needs to go with the strategy that they can afford that can align with their financial capability. Those who apply the DCA method of investing are active investors that are ready to buy bitcoin from time to time , while the lumpsum are investors that can afford to buy bitcoin with a particular amount and hodl for a longtime to make good profits.