Really, I do not understand your reasoning since the S&P 500 has an annualized return of >10% since 1970.

https://en.wikipedia.org/wiki/S%26P_500_Index#Annual_returns

Just because the S&P has seen such returns over the last 40 years, doesn't mean you'll see those returns over the next 40 years. The US economy is aging out, has stagnant wages, etc.

Also we saw a huge drop in interest rates that won't happen again over the next 40 years.

Going to disagree with you here. I think it'll be impossible to raise interest rates much further without causing economic damage. See negative interest rate policies in Japan and Europe, and close to zero rates still in the US.

I 100% agree with you about the difficulty of raising rates. But I don't think they'll continue to drop like they have over the past 30 years.

I have a hard time imagining a world of -5% to -10% rates!

> I have a hard time imagining a world of -5% to -10% rates!

A year ago I would've agreed with you, but with the ECB at -.04 and Japan at -0.02, I believe it more likely than previously.

Heh, fair enough. It's certainly very surprising to see rates below zero. So, indeed, I am much less certain about the future!

Incorrect, please re-read my statement. An average 10% annual return over 10 years. As the other reply to this notes, history shows in general this rule has held since 1970ish.