This thread might be interesting for you. It has participation from ex-bridgewater employee.
https://www.bogleheads.org/forum/viewtopic.php?f=10&t=206028#p3158933
Tks, he is correct. Dalio loaded in stuff like TLT in his retail all-weather to try to mimic leverage. I dont to a lot of reading on AA these days because I find most articles quite bad. Most use that portfolio analyzer website to backtest things but that only goes back to 1970. This creates a very unfair backtest. But more importantly, I have run extensive backtests going back to 1926 and 1879 and I had a number of lessons that I learned. But the most important one (which guides my portfolio design today) is that what works is to try to build a Taleb 'barbel' style portfolio.
The reason the Dalio portfolio and my own basic AA (55% 10y bonds, 30% stocks, 15% gold) do great in terms of risk adjusted returns its because it has a drawdown anchor (bonds mixed with gold) and a high risk high return asset (stocks) at an
appropriate ratio. So the holy grail and debate should not be (should I add 5% of TIPs? What about EMs? What about the latests corporate bond ETF non-financial BBB+ rated thing from blackrock?) but rather, how much of drawdown anchors do I want to own how much of high risk high return (what I call convexity) do I want to own
If one thinks about it, the best portfolio on earth (in terms of risk adjusted returns) is 99% extreme safety (say inflation linked bonds of several developed economies) and 1% extreme risk (say, technology startups). Drawdowns will be extremely contained while the chance to gigantic payoff still exists (if one catches the next FB), the result is great risk adjusted returns (high sortinos, MAR, Sharpe, etc). Thinking in terms of drawdown anchors + convexity to me its a lot more useful than obsessing with which ETF is being purchased