But there's a small problem that might bother some investors. The average price-to-earnings ratio and price-to-book value ratio of Vanguard S&P 500 ETF are 27.7 and 4.9, respectively. For Vanguard S&P 500 Growth ETF, those figures are 34.6 and 9.4, respectively. The growth-focused version of the S&P 500 is looking really expensive right now.

A seemingly unstoppable flood of money has Vanguard Group Inc. on the brink of claiming a crown that State Street Corp. has held for decades.

Vanguard exchange-traded funds (ETFs) are a fantastic choice for retired investors looking to play the long game with their portfolios. Undoubtedly, Vanguard is a name that passive investors can put their trust in.