Sak,
Different businesses have very different attitudes towards their grad recruitment. This ranges from places where the costs are relatively high i.e. above 1.20/round turn and desk fee above 2k to the more reasonable 0.90/rt and 1.5k fee.
Certain places will look to retain maybe 1 in 10 or less and make it very difficult to survive due to excessive costs as well as only being prepared to invest a few 1000 in drawdown while new people train. If you exceed those parameter then they show you the door unless you realise before that, that you are working your arse off but not making anything yourself while you are paying huge costs.
The place where I rented space until very recently had had people come from other arcades who had not been able to make money and they helped them turn that around into making a good living.
They started a grad scheme at the beginning of 2003 and not a single one has left or been booted out. This is because they have a desire towards creating a reputable and sustainable business and are prepared to invest in the grads they take on. It would not be right for me to say exactly how much those particular grads made in their first year, but I will say that for the first 6 months their account shrank considerably, some to less than 50% of the initial value. It was the second half of the first year when things started to really pick up and now they are all doing better than they could have hoped in most other grad jobs. Lets say that a reasonable expectation for a competent trader in the first year is earning a living and second year is 50-100k. I am only talking from the perspective of the people I have seen go through that process so do not take this as standard in any arcade, they all teach different techniques and some give no training at all.
Anybody considering this option needs to be very careful about the contracts they are signing and do not think that the opportunity is so great you simply have to sign anything that is put in front of you, it is not, you are a revenue generator for the business and that is it. They will try to pick the people who they think have the right personality type to aggressively trade and generate lots of business. Qualifications do not mean much at all in this respect.