If you had DCA'd into the Japanese market you would still have made money. So perhaps the argument is that lump sum investing is too risky? Even though studies show it outperforms compared to DCA that is only true when the market is continually going up (which most of the time it does) but if you're somewhere where it does not do that like Japan then there is an edge of DCAing over lump sum.
I stopped reading when you didn't consider dividend for Japan's index.
If you had DCA'd into the Japanese market you would still have made money. So perhaps the argument is that lump sum investing is too risky? Even though studies show it outperforms compared to DCA that is only true when the market is continually going up (which most of the time it does) but if you're somewhere where it does not do that like Japan then there is an edge of DCAing over lump sum.
Curious to hear your thoughts.