I've seen portfoliovisualizer and portfoliocharts, but I'm looking for a backtesting site that allows me to account for today's negative real returns on bonds instead of assuming the interest rates of the past, which nobody can get today. With 10y treasuries yielding 1.57% in an environment where 2-3% inflation is likely, I don't know that we can rely on historical portfolio performances, because:
a) in most historical periods, bonds had 2-4% real returns to prop up a 4% WR, and...
b) in most historical periods, recessions were accompanied by 1-3% reductions in interest rates, which caused bonds to appreciate greatly, setting up profitable rebalancing opportunities. Now there's a lot less room for rates to fall.
Does anyone know of a monte carlo portfolio simulator that allows one to enter their own estimated rate of return for bonds? I recall seeing one in the past, but cannot remember its name.
