Investors trust advisers more than politicians, about the same as mechanics, and less than doctors, lawyers and accountants, a CFA Institute study says. Do you really need one? For some, yes. For others, maybe not. Let me explain.

If you are younger than 40 and are investing for retirement, then the answer could be no. You can buy and hold a broad-based low-fee equity ETF like Vanguard Dividend Growth (VIG). Young investors don’t need to hold today’s low-yielding bonds.

Are you generally optimistic or pessimistic? Optimists do better because they aren’t distracted by the barrage of negative headlines on days that stocks retreat. Sure, there are well known pessimists (Dent, Gartman, Faber, Hussman, etc.) but they are known for eye-popping interviews instead of good portfolio performance. I wouldn’t want them to manage my money.

Along the same lines as being an optimist, a good investor understands that over the long-term the market goes up. Those that say “what goes up must come down” are wrong. In 1950 the Dow stood at 200. By 1970 it rose to 800. In 1990 it was 2,800. Now it’s 34,000. Get the point?

So if you are young, optimistic, and either don’t follow the market or don’t panic when it falls then you can do very well by buying a low cost broad-based index fund and let the power of compounding work for you. This isn’t controversial. Most investors do this. That’s why S&P 500 index funds are the largest. Still, this approach drives some people nuts. They want to outsmart the market.

Why not “time” the market by jumping in and out? The problem: you have to be right twice. Getting out is the easy part. You might take profits now expecting a pullback and some kind of retreat usually happens. You feel good. But the hard part is getting back in.

If the market continues to go down then investors feel better about holding cash. But if the market goes up investors don’t want to admit they were wrong so they don’t get back in and wait for a pullback instead. Either way, they don’t get back in. I can’t tell you how many times I’ve seen this. Instead of jumping in and out, it is better to own a portfolio that you are comfortable with during both ups and the downs.

So who needs a financial adviser? If managing money is a source of stress then an adviser can be helpful. If you’ve tried to manage your money but are unsuccessful, for whatever reason, then having an adviser is a good idea. Finally, if you are in retirement and in need of income then investing is trickier. An adviser can help you generate income from your investments, limit draw-downs, and make sure you take required withdrawals. That describes the majority of my clients.

You can see that the choice of whether or not to use an investment adviser comes down to your personality more than it does to your investment knowledge. For some there is no reason to pay an adviser. For others, it is money well spent.

David Vomund is an Incline Village-based Independent Investment Adviser. Information is found at http://www.VomundInvestments.com or by calling 775-832-8555. Clients hold the positions mentioned in this article. Past performance does not guarantee future results. Consult your financial advisor before purchasing any security.