Launched on September 9, 2010, the Vanguard S&P Mid-Cap 400 ETF (IVOO) is a passively managed exchange traded fund designed to provide a broad exposure to the Mid Cap Blend segment of the US equity market.The fund is sponsored by Vanguard. It has amassed assets over $2.78 billion, making it one of the average sized ETFs attempting to match the Mid Cap Blend segment of the US equity market.Why Mid Cap BlendWith market capitalization between$2 billion and $10 billion, mid cap companies usually contain higher ...