Stocks.  However, stocks have a volatility (risk) level about 4 times that of investment grade bonds, so real gains come at a price.

Commodities.  The CRB commodities index has shown negative cumulative returns since 1926.  Except for a blip up during the early 1970's, their trajectory has been mainly downhill.

This is the northwest most point where optimal portfolios maximize reward-to-risk.  This is the point where you maximize your investment portfolio's returns for the amount of risk that you take.  WMB and the portfolios mentioned in the chapter come pretty close to doing this.

You would need a 100% return, not a 50% return to get back to break-even.  From 100 to 50 is a 50% drop, but a rebound from 50 to 100 is a 100% gain.  Try doing the math!

Swensen's investment portfolio has a perpetual time horizon - so he can afford to take on much more risk than an individual can.  This is especially true for seniors, who face a limited time horizon and who may not be able to participate in a full recovery from a bear market.  Also, the Yale portfolio invests in many alternative and private equity investments that are not suitable for most individual investors - they are more suitable to institutional investors.

Jones' ALl Weather portfolio has a 45% allocation to stocks, which is much more than WMB and Dalio's 30% allocation to stocks.  All Weather does better in bull markets, but in bear markets the volatility can be quite excessive - which means that this approach is less suitable for seniors due to more limited time horizons.

The real reward-to-risk ratio measures the average annual returns of an investment strategy after inflation, divided by the standard deviation (or volatility) of the returns on an annual basis.

The real profit factor takes the summation of an investment strategy's annual returns after inflation, and divides that by the summation of all the down years after inflation.

WMB has come in first with a real reward-to-risk ratio of  1.08 vs. All Seasons' 0.99 and All Weather's 0.45.  The real profit factor tells the same story: WMB in first place with a real PF of 12.62 vs. All Seasons' 8.92 and All Weather's 3.51.