Long term US bonds are definitely the most prominent example for the last 40 years. Past 100 years though, not really. Check the ETF TLT compared to total US s

Long term US bonds are definitely the most prominent example for the last 40 years. Past 100 years though, not really. Check the ETF TLT compared to total US stock market, VTI, on https://www.portfoliovisualizer.com/backtest-portfolio https://www.portfoliovisualizer.com/backtest-portfolio or the asset classes on https://www.portfoliovisualizer.com/backtest-asset-class-allocation https://www.portfoliovisualizer.com/backtest-asset-class-all... Their negative correlation zig-zag is remarkable the past few decades. Some research postulates that in a decreasing interest rate environment (past 40 years), they’re negatively correlated, while in a rising rate environment they’re positively correlated, leading to the past 100 years minimal (almost 0) long term correlation.