Which type of investing involves following a one to one relationship with a benchmark?

Investing that involves following a one-to-one relationship with a benchmark is characterized by obtaining similar returns to that benchmark rather than attempting to outperform it. This approach is typically referred to as a "pure play on beta," where the investment strategy is designed to replicate the risks and returns of a specific index or benchmark.

The concept of beta represents the volatility or systematic risk of a security or portfolio in comparison to the market as a whole. A pure play on beta means that the investment is highly correlated with the benchmark, effectively moving in tandem with it. This strategy emphasizes mimicking the benchmark's performance rather than taking on active management practices that involve stock selection or market timing decisions.

By aligning closely with the benchmark, investors can achieve the desired market exposure while minimizing the idiosyncratic risks that come from actively managing a portfolio. This approach is often used by passive investment strategies, such as index funds, which aim to match the performance of specific benchmarks, thus providing a low-cost investment vehicle that avoids the complexities of active management.