I am trying to work out how to determine weights for the assets in order to form a portfolio. The ratio I am using is EV/EBIT, hence the smaller the better. The problem is I don't know how to handle it when EV < 0. Obviously that is kind of a 'free lunch' mathematically speaking and I realise the discontinuity at x/0 is what messes things up in a way. Would anyone be able to suggest something?