So what must your monthly, weekly or daily return be to double you capital over 1 year?
12 months, with 20 avg trading days each, and say you start with R100k and want to end with R200k, then your monthly return should be about 6%, which gives you around 0.3% per trading day, net after costs. The calculation is simple. Doubling your capital year on year is not. Below is the monthly overview, at 6% per month: