Any finance professional will tell you that if you want to grow your wealth, your asset allocation needs to include stocks. The reason is simple – stocks have the highest potential return. In the many articles on how to invest for your retirement, a common recommendation is to get stock market exposure through a low-cost index fund. There are good reasons for that, but buying actively managed funds or individual stocks are also valid approaches, with different benefits and drawbacks. I want to discuss some of those here. I’m not a financial advisor, but this is my take based on what I’ve read and my own investing experience.

Before we get into that, I should point out that we’re only talking about the stock portion of a portfolio here. The concept of asset allocation – how much to invest in stocks versus bonds versus anything else – is a topic for another article. Similarly, I’m ignoring targeted maturity funds, since they take care of asset allocation for you. I’m also ignoring exchange-traded funds (ETFs), which can be a good alternative to index funds.

Index funds have a lot going for them. First, since they don’t have to do a lot of research to determine what stocks to put in the fund, they typically have the lowest expense ratios (the amount you pay to own the fund). The low turnover of index funds makes them tax-efficient, so they can be good choices for taxable accounts. Index funds are also basically guaranteed not to under-perform the market. Morningstar found that 75% of actively managed large-blend funds failed to match the returns of the S&P 500 index, so knowing that your fund won’t under-perform brings some peace of mind. This also means you don’t have to do a lot of research into different funds, because all the funds that track a particular index will be very similar. And of course, buying any fund has the benefit of built-in diversification – you’re not overly exposed to a meltdown of any single company. All these factors combine to make index funds about as close as you can get to fool-proof investing.

Index funds do have one disadvantage, though. You’ll never beat the market with an index fund. Following an index can be risky when that index becomes overvalued. When a bubble develops, you’re buying into that bubble, and you’ll suffer the ensuing bear market when the bubble bursts.

That brings us to actively managed funds. The big advantage of such funds is that they can beat the market, which becomes especially important in a bear market. Look at Fairholme (FAIRX) for an example of how a good actively managed fund protects you from the bear. When the tech bubble burst, the S&P 500 lost 9% in 2000, nearly 12% in 2001, and a full 22% in 2002. Fairholme only lost money one year, in 2002 – a mere 1.6%. While index investors watched over a quarter of their money evaporate, investors in this fund actually made money. And with actively managed funds you still get the built-in diversification.

The problem? Most funds don’t perform as well as Fairholme has over the long term. As mentioned above, a full 75% can’t even match index returns, much less beat them. This means investing in actively managed funds takes a lot more research. You have to look for good managers, and examine how the fund and the management team has performed, especially during bear markets. Even when you find a good fund, it won’t necessarily perform as well in the next bear market as it did in the last. You also have to watch the fund for changes – your research time doesn’t end when you decide to invest in the fund. If new managers take over, the fund you originally chose might not be a good investment any more. The investment style of a fund might also change, putting it out of sync with the rest of your portfolio or your risk tolerance. Actively managed funds carry higher fees than their index counterparts, and some of them can have high turnover, generating lots of taxable income. If you’re not careful, it’s very easy to end up investing in a fund that lags its index while costing you more money.

The ultimate low-cost option is, of course, buying individual stocks. You’ll pay brokerage commissions to buy and sell, but there is no management team taking a small part of your assets every year. Assuming you use a buy-and-hold strategy, you can usually more than make up for the brokerage commissions by avoiding fund expenses. Buying your own stocks also gives you total control over your capital gains – no need to worry that your fund manager is going to dump a big taxable gain on you.

The big downside to stocks is the amount of research time you have to put in. First, you’ll need to choose about 20 stocks to be properly diversified, assuming an equally-weighted portfolio – that means lots of research time right up front. Then you’ll need to keep a close eye on your choices, watching for changes in management, financial health, competition, as well as the stock price so you know when it’s time to sell. You may also need to watch other stocks, keeping an eye out for bargains so you can buy in at a good price point. If you want exposure to foreign stocks and small caps, expect to spend even more time on research, since it is much harder to get good information on these types of companies. Stocks also have high individual volatility, so it can take an iron will to ignore the daily noise of the financial press and stick to your convictions. If you’re investing small amounts of money on a regular basis, those brokerage commissions can really add up. And it’s entirely possible your return won’t keep up with the index, just like most managed funds.

So, what is the best choice? I think it comes down to how much time and effort you want to spend dealing with your investments. Index funds take almost no time or effort and automatically get you market-matching returns, so they are probably the best option for most people. Personally I tend to go with actively managed funds. It takes more research, but a good one can help you avoid the perils of a risky bubble – while a bad one just makes you pay for worse returns than the index. I have a friend who loves avoiding fund fees and capital gains by going the individual stock route. Stocks take the most research and carry the most risk individually, but if you diversify appropriately you can get the benefits of a fund without the extra cost.

And no, at the time of this writing, I didn’t own any shares of FAIRX… though it’s definitely on my list of potential future investments.