I had a conversation with a co worker about this. Its basic probability. Lets assume they make at least 1 trade a day and they have been doing this for the past

I had a conversation with a co worker about this. Its basic probability. Lets assume they make at least 1 trade a day and they have been doing this for the past 25 years. Its a simple binomial probability problem. For them to be correct on that many trades and it to be 'luck' would be a probability in the ~0.00001% range.