Although I'd appreciate hearing from anyone, I'd especially be interested in folks like us, with a ~$1M portfolio, who started this strategy in the past few years, and for whom it seems to be working well. The previous decade of crazy gains was waaaay too much of a best-case scenario, so I'm less comfortable with data from those years.
20 years ago I read "The Millionaire Next Door" and that book inspired me to start taking control of my saving and investing. Then I read "The Armchair Millionaire" and that book gave me direction on how to invest for my future.
The basic premise of "The Armchair Millionaire" is simple:
1/3 in a Large-Cap US Index fund.
1/3 in a Small-Cap US Index fund.
1/3 in an International Index fund.
(feel free to choose funds from whatever brokerage you use)
While "Armchair" recommends 100% in equities, (which I did from age 30 to 45) you can still follow their strategy within the equities portion of your portfolio. At age 45 I switched to a 75/25 stock/bond ratio which was allocated as follows:
25% in a Total Bond Market Index fund
25% in a S&P 500 benchmarked index fund
25% in a Small-Cap Index fund
25% in an International Stock Index fund
Currently I'm at a 60/40 stock/bond ratio but I still use the same strategy as shown below:
40% in a Total Bond Market Index fund
20% in a S&P 500 benchmarked index fund
20% in a Small-Cap Index fund
20% in an International Stock Index fund
This is what I've done from the early 2000s. My funds are primarily in Vanguard and John Hancock 401(k) accounts and a Vanguard Roth IRA. If I review my performance from the past 10 years (that's as far as the calculator will let me go back) I'm averaging 11.2% rate of return. I'm sure others will have allocations which are similar to this, and others will have completely different allocations. In the year 2000 I had ~$12K in my first 401(k). I've contributed as much as I could afford over the past 21 years. Some years I have been able to max-out my contributions and other years I wasn't able to reach the limit but I always contributed at least 10% of my income. Today I'm at $1.3M and looking to retire in 2025 at age 54.
As a wise person on this site likes to say, "YMMV"