If I were starting over today with a few hundred dollars, I'd buy exactly what I tell every new investor to start with: the Vanguard Total Stock Market ETF (NYSEMKT: VTI). A recent piece on AOL arrived at the same conclusion, and it got me thinking about why this fund keeps coming up as the answer.

VTI tracks the Morningstar US Total Market Index. That means it holds almost the entire U.S. stock market, from Apple and Microsoft at the top down to small companies most people have never heard of. You get large caps, mid caps, small caps, and micro caps in a single purchase. The expense ratio is 0.03 percent, which works out to $3 per year for every $10,000 invested. Three dollars. That is not a typo.

Put that in perspective. If you have $50,000 invested, you are paying $15 a year in fees. Many actively managed mutual funds charge substantially more than that. The difference leaves your account every year regardless of whether the fund performs well or poorly. Over decades those fees compound right alongside your returns, except they work against you instead of for you.

What makes VTI work is the lack of complexity. You buy one ticker and you own a piece of the entire U.S. stock market. When large caps are flying, you participate. When small caps eventually catch fire, and they do, you own those too. You never have to rebalance between asset classes or guess which sector is about to rotate. The market does the work.

People ask me all the time whether they should add individual stocks to their portfolio. I own a few, and I've written about some of them here. But individual stocks are a side bet. The foundation, the thing that actually builds wealth over decades, is broad market exposure. Boring, steady, low-cost exposure that you add to every month whether the market is up or down.

The investors who come out fine over the long run are rarely the ones who timed the market or picked the winning stock. They are the ones who kept buying. VTI, or something like it, makes that simple. Every major market decline in the past few decades, the kind that makes people want to sell everything, eventually recovered. The people who kept adding money during those downturns came out ahead of the ones who went to cash and waited for things to feel safe again.

Some investors argue that a total market fund leaves too much on the table because it is market-cap weighted. You end up heavily concentrated in whatever the largest companies happen to be at any given moment. Right now that means a lot of exposure to tech. There is some truth to that. But for a first investment, broad ownership beats clever allocation every time. You can always add complexity later once you understand what you own and why.

If you're starting out, or starting over, the path is straightforward. Open an account. Buy VTI. Keep buying it. Do it for twenty or thirty years and let compound interest handle the rest. That is not a hot take or a secret formula. It is just the thing that has worked for more people than any other approach.

As always, I'm sharing perspective based on my own experience, not professional financial advice. Talk to a licensed advisor about your specific situation before making investment decisions.