Related: The Battle of Acronyms: SRI Vs ESG

Plain vanilla index ETFs that track the value theme has outperformed so far this year, or at least have not done as poorly as broader benchmarks. Nevertheless, potential investors should still look under the hood of these value stock ETFs as no two are created alike and offer varying performances.

Rival value ETFs include the Schwab U.S. Large-Cap Value ETF (NYSEArca: SCHV) and the iShares S&P 500 Value ETF (NYSEArca: IVE), among others.

“Since 1995 the average ratio between S&P Value and Growth price-earnings (P/E) ratios has been 0.45, i.e. value typically trades at a 55% discount to growth. Currently the ratio is 0.30, close to two standard deviations below the long-term average. Value has not been this cheap relative to growth since early 2000,” according to BlackRock.

For more on smart beta ETFs, visit our Smart Beta Channel.