what is the difference between the modern portfolio theory and the post modern portfolio theory 
the modern portfolio theory mpt was a breakthrough in personal investing it suggests that a conservative investor can do better by choosing a mix of low risk and riskier investments than by going entirely with low risk choices more importantly it suggests that the more rewarding option does not add additional overall risk this is the key attribute of portfolio diversification the post modern portfolio theory pmpt does not contradict these basic assumptions however it changes the formula for evaluating risk in an investment in order to correct what its developers perceived as flaws in the original followers of both theories use software that relies on either mpt or pmpt to build portfolios that match the level of risk that they seek 