The Vanguard Energy ETF ( VDE -0.68%) mirrors the sector's performance. So far this year, it is the best-performing exchange-traded fund (ETF) offered by investment management firm Vanguard. And with a 3.2% yield and a mere 0.1% expense ratio, it offers an inexpensive way to generate passive income.

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.

Vanguard is one of the gold standards when it comes to low-cost exchange-traded fund (ETF) options. Undoubtedly, passive investing (typically with index funds) tends to be wildly popular among the retail crowd.

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.