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.

If you're new to investing and don't have a lot of money to get started, don't fret. The best place for new investors to begin is often with exchange-traded funds (ETFs), which will give investors instant diversification through a portfolio of stock holdings.

If you've been an investor for any length of time at all, then you've almost certainly been advised to start (and maybe even finish) with index funds like the Vanguard S&P 500 ETF. This fund is of course simply meant to mirror the performance of the S&P 500.