The percentage is debatable, and it varies. Maybe, it is around 96%. Whatever be the case, one thing is for certain: a lot of traders lose money in forex trading. They mostly fail because of greed and an unrealistic approach of the market.
Perhaps the answer to this question should have three components instead of two.
Rather than:
~ 90% lose
~ 10% win
Instead:
~90% lose
~9% earn a small or modest amount of money during the current year
~1% or less earn an amount equivalent to a middleclass salary or better
I suspect that the latter scenario is closest to reality.
Strategies that didn’t work in the beginning might work later in your career. It’s not just about the right strategy but also about using it at the right time in the right trade.
PS: Traders who don’t understand this are those who make 90% of the failing forex traders.