If you're looking for just one exchange-traded fund to own in your portfolio, the Vanguard Total Stock Market ETF is still one of your best bets. This fund covers a wide swath of the domestic stock market, giving you exposure to more than 1,000 companies in one swoop. What better way to get broad-market exposure for a rock-bottom cost?

Fund Name & Ticker Vanguard Total Market Stock ETF (NYSE: VTI)
Fund Objective The fund employs a passive management strategy to track the MSCI US Broad Market Index, which consists of all common U.S. stocks traded on the New York Stock Exchange and Nasdaq over-the-counter market.
Recent Price $67.03
Assets Under Management $150.4 billion*
P/E Ratio 18.1**
ROE N/A

Source: Vanguard.
*Includes both ETF and mutual fund assets.
**Aggregate P/E for all fund holdings.

On the winning track
Since the fund was first recommended as a core ETF last fall, Vanguard Total Stock Market ETF has risen roughly 13.5%, compared to the S&P 500's 12.5% gain. That's not a huge difference, but even a single percentage point can add a lot to your portfolio over time. The reason for this outperformance comes from the fund's nearly 30% allocation to mid- and small-cap names, which have outpaced their large-cap brethren in recent months. This won't always be the case, but over the long run, the fund's wider mandate means it should stay just ahead of a large-cap-focused index like the S&P 500.

It's important to remember that this fund's directive isn't to outperform the market, but merely to track the path of the broader U.S. stock market, including mid- and small-caps. And over its almost 10-year life, the fund has accomplished that goal admirably, posting a 3.1% annualized gain since its May 2001 inception. That's more than double the return of the average large-cap blend fund in the Morningstar universe, and it speaks to the importance of having a diversified portfolio that covers all the stops in the market capitalization spectrum.

Big-name blue chips like ExxonMobil, Apple, and Microsoft still take center stage here, and they'll continue to dominate the fund's largest positions, thanks to the underlying index's market cap-weighting scheme. However, mid-cap and small-cap names still have enough presence here to make a difference in performance.

Vanguard Total Stock Market ETF retains it low 0.07% price of admission. That makes it one of the absolute cheapest options around for wide-ranging stock market exposure. It's hard to go wrong with such a low-cost, broad market exchange-traded fund, and this fund is still one of the best options around. If you have just one ETF in your portfolio, make it this one.