Investing is not easy.

The two quilts below, regularly published by John Stoltzfus, the chief investment strategist at Oppenheimer, illustrate this.

The first one ranks how individual asset classes have performed in each year of the past decade, while the second shows the same for S&P 500 sectors.

The main takeaway, gleaned from how often the colors change, is that no single asset class or sector is guaranteed to produce the most returns in any given year. It also shows the challenge of forecasting based on past performance.

“In our view, the quilt illustrates the importance of portfolio diversification and regular rebalancing,” Stoltzfus wrote. “On its own, each asset class can be quite volatile, but a mix of assets in a balanced portfolio can lower overall volatility.”

Here are returns across asset classes:Screen Shot 2017 03 23 at 7.57.26 AM

Foto: sourceOppenheimer

And this shows equity returns across sectors:Screen Shot 2017 03 23 at 7.57.37 AM

Foto: sourceOppenheimer