the 3 month period is more than sufficient to support the counter-argument. in the 2011 report they include changes from the prior quarter which doesn't show a major fluctuation. this data is more substantial than the lack of data supporting the 95% myth
My understanding is as follows. A broker has for example 100,000 clients. In the 3 month period Jan-March maybe 25,000 clients are profitable over that period. They report that as 25% profitable.
In the period April-June 28,000 are profitable over that 3 month period. The 25,000 who where perviously profitable may or may not form part of the new 28,000. The previous 25,000 profitable traders could have all blown their accounts by this stage.
The only way you'll ever know is if the broker discloses anonymised data. There's absolutley no reason (other than committing commercial suicide) why they cant provide this data. Ask any broker representative posting here at t2w direct questions on this issue and they'll run a mile.
Ask the direct question how many are profitable after 3,6,9,12,15,18,21,24 months etc. If the brokers could report how many clients where profitable on a day by day basis they would, but the longer the reporting frequency, the worse its going to look for them.
Every source of verified statistical data, CTA records, long term fund performance etc backs up the 95% fail argument. Its a case of being fooled by randomness, and a 3 month window is more than enough to pull the wool over the eyes of most of their punters.