Whenever I write about indexing with an advisor, I get questions from readers who wonder why passive investors would work with a professional. After all, in most cases, you’ll pay an advisor about 1% assets under management—and that’s on top of the MERs on the ETFs or mutual funds. Index investors, who are especially keen to avoid fees, wonder aloud if that’s worth it.

Here are a few ways passive investors can benefit from the help of an advisor:

Emotional control. The theory of index investing is simple: build a low-cost, well diversified portfolio and stick to the plan through all the ups and downs of the market. But in practice, this is incredibly difficult for most people. Rebalancing is particularly hard, because it invariably means adding money to asset classes that are out of favour. When everyone is screaming at you to get out of bonds or international equities, can you plug your ears and stay the course? An experienced advisor—and an Investment Policy Statement—can remove the emotional obstacles that impede even seasoned indexers.

Risk management. If you need a 4% return to meet all of your financial goals, how much of your portfolio should be in equities? If you’re 10 years from retirement and you have a small pension from your employer, how much of your RRSP should be in fixed income? An advisor can help you determine the target rate of return you need, and then build an index portfolio designed to meet your goals by taking just the right amount of risk.

More efficient portfolios. Index investors with small accounts should keep things simple. But for those with large portfolios, it can make sense to diversify more widely, and this can make portfolio management difficult for the DIY investor, especially if the investments are spread across a number of accounts. Large indexed portfolios may include emerging markets, foreign bonds, real-return bonds, real estate, a blend of large and small caps, value and growth, and so on.

Performance monitoring. At a recent investment show, when I asked the audience of DIY investors if they thought their portfolios had beaten the market over the last five years, about three-quarters of them raised their hands. It’s possible that I stumbled into a roomful of Warren Buffetts, but I suspect that most of these folks were overestimating their returns. A good advisor will provide you with regular feedback about how your investments are performing, which will you create a realistic plan your financial future.