From what I understand, the global economy has become so intertwined that 90% of the time domestic and foreign markets will mirror each other anyways. The example I was given is that the Taiwanese life insurance industry is larger than the US mortgage industry and how they both affect global markets. I personally like a mix of S&P500, treasury bonds index, small cap domestic, and a foreign stocks index. And a good robo that gives me that mix with a 0.07% fee or whatever like VTI does could be great. But if the fees are higher than that, I’ll balance it myself.