Measuring the Size Effect with Capitalization-based ETFs

Do popular capitalization-based exchange-traded funds (ETF) offer a reliable way to exploit an equity size effect? To investigate, we look at the difference in returns (small minus big) between:

• iShares Russell 2000 Index (Smallcap) Index (IWM), and
• SPDR S&P 500 (SPY)

Using monthly dividend-adjusted closing prices for these ETFs during May 2000 (limited by IWM) through March 2022, we find that: (more…)