The largest hedgefund in the world, Bridgewater Associates, run by Ray Dalio has an All-Weather Porfolio which is supposed to have low volatility and beat the market by small margin over the long-term. The All-Weather portfolio uses complex instruments but according to Ray Dalio it can be simplified using these 5 ETFs:
1. 40% in Long-term government bonds $TLT
2. 30% in the S&P 500 $SPY
3. 15% in intermediate government bonds $IEF
4. 7.5% in Gold $GLD
5. 7.5% in Commodities $$DBC
I have tried to build one of my own 2 years ago using some more ETFs and making it more dynamic with monthly $150 addition ($5/day). Here's what I can say from this experiment:
While it has been working, comparing it to my main portfolio doesn't really work anymore given my massive gains in January 2021 with GameStop $GME . It can still be compared with the S&P 500 as a benchmark.
However, I'm not a macroinvestor and I would rather look for individual companies than invest in a low volatility ETF portfolio. It can work if you're interested in it but for a value investor, I don't think this is interesting.