If someone came to you and said they had $1,000 to invest and wanted your help in deciding where to put it, what would you tell them?

Based on recent market returns, your inclination might be to say a tech exchange-traded fund (ETF), such as the Vanguard Information Technology ETF (VGT -0.02%). Since they’re just starting out, you might suggest more of a foundational piece, such as the Vanguard S&P 500 ETF (VOO -0.41%).

I think the latter choice is certainly defensible. You want to start your portfolio with something that’s broadly diversified, ultra-low cost, and can be held for decades or more. The tech ETF probably isn’t a good choice for a starter portfolio (at least as the first fund to own). It’s far too focused on a riskier…