bkballa

slope is (chg in value of assets / chg in value of stock mkt). So since 60% is in stocks, when market goes up by 20%, value of assets will incr by 12% (i.e. 60% of 20%).
I think the payoff diagram is just a ‘snapshot’ for a pt in time, so once the market shifts, since it’s a buy and hold strategy, your allocations will change and the ‘slope’ of your portfolio will be different.