I believe everyone who says that they are a “day-trader” has not profited from the market more, if back-tested, against a “buy the dip and HODL” strategy, from March to December 2020. The more trades, the more mistakes.
You are talking on the negative side but we know that you can earn more than on the amount that you can make with just simply buy the dip and hold.
It is just normal that you would really be dealing with higher risk since you do actively engaging in the market and dealing up with price on active manner which is totally
opposite into those who do tend to hold or somewhat playing on the safer side.
When it comes to effectiveness then this will vary or depend on someones capacity or capability on doing trades. Trading styles can neither effective or not on trying out
each of those ways that had been mentioned by a certain individual.