How's that?
You can/should play around with DCA.
If you know nothing about a stock you’re better off with simple DCA because without it you might be buying with a lumpier sum at historically high multiples at the end of a bull run.
If you do know a thing or two about the stock you can do the bulk of the purchase upfront if the stock is historically cheap or after a leg lower and then add on the rest as time progresses, or if the multiple is stretched and you’re well into a bull run, start out slow and if it takes a dip you buy with a bigger lump.
Don’t treat Dollar Cost Averaging as a rule, treat it as a concept.