Quote from EricP:
How does one calculate the percentage of losing traders, assuming all of the data is in hand?
For example, let's assume the following history for a prop firm:
Year 1: The firm opens. 100 traders begin trading. 90 fail miserably and go away. Ten have some level of success and continue trading with the firm.
Year 2: In addition to the 10 net profitable traders from the prior year, another 100 new green rookie traders join the firm. Of the rookie traders, 90 fail miserably and 10 have some level of success and continue trading.
Year 3: In addition to the 20 net profitable traders from the prior year, another 100 new green rookie traders join the firm. Of the rookie traders, 90 fail miserably, while 10 have some level of success and continue trading.
etc, etc, etc
Year 9: In addition to the 80 net profitable traders from the prior year, another 100 new green rookie traders join the firm. Of the rookie traders, 90 fail miserably, while 10 have some level of success and continue trading.
So, the question is: "What percentage of traders actually lose money?" => In Year 9, one might conclude that 50% of all traders are profitable (80 experienced traders + 10 rookie traders made money while 90 rookie traders failed). However, someone could also look at all of the data for the firm and see clearly that 90% of all traders that came into the firm lost money.
Obviously, this is a simple example, but I suspect most people looking at all the data would say that 90% of all traders lose money, not 50%.