> an app on my phone that instantly calculates futures prices and margin requirements for given position sizes and predicted market movements.
That sounds like something for which one should be spending the money on professionally developed and well-tested software. What's the expression? Penny wise, pound foolish.
Not really, because the equations are straight forward and not particularly difficult. Most people could model it in excel no problem. Is it a guarantee that it is robust? No. But I'm also only using it myself instead of ball parking like I previously would.
That sounds like something for which one should be spending the money on professionally developed and well-tested software. What's the expression? Penny wise, pound foolish.