Key Points iShares Morningstar Small-Cap ETF and Vanguard Small-Cap ETF share nearly identical expense ratios of 0.04% and 0.03%, respectively. Vanguard Small-Cap ETF manages $182.7 billion in assets under management (AUM), making it significantly more liquid than iShares Morningstar Small-Cap ETF, which manages $277.7 million in AUM. The iShares Morningstar Small-Cap ETF provides broader exposure with 1,544 holdings compared to the 1,357 companies in the Vanguard Small-Cap ETF portfolio.