IVOV is a viable choice to get exposure to mid-cap value companies. The Underlying Index selects stocks from the S&P mid-cap 400 (the parent index) that exhibit these fundamental value characteristics: book value, earnings, and sales to price ratio. The fund's portfolio has a slightly less value exposure due to the S&P Style Indices methodology that divide the complete market capitalization of each parent index into growth and value segments resulting in a basket of stocks that overlap with core and growth funds. The underlying index is market cap-weighted and undergoes annual rebalance on the third Friday of December. Like all Vanguard ETFs, IVOV only discloses its holdings monthly, instead of daily.