There are several internal factors that dictate how you allocate your portfolio. The evolution of these variables (age, net worth, risk profile, etc.) over time will also change where you fall on the active-passive spectrum.

For many investors, the best solution very well might be robo-advisors. If you have a smaller net worth or don’t require much financial planning, the diversified investment options provided by robo-advisors is as cost-efficient and passive as you’re going to get.

A higher-net-worth individual, on the other hand, is likely to have more needs. Optimizing a portfolio for complexities like estate planning and tax efficiency will require a more active approach to how assets are allocated. The high-net-worth clients I work with typically require a more diversified allocation beyond stocks, bonds and cash into assets such as real estate, insurance, private equity and other alternatives.

And then, of course, you have to consider the external factors (i.e., market conditions) when thinking about an active versus passive approach. Historically, active strategies tend to perform better in down markets while passive strategies outperform in up markets. Morgan Stanley found that over the last 20 years, the top 25 percent of portfolio managers significantly outperformed their benchmarks in years when the market was down.

The period from 2009-today has been one of the longest U.S. equity bull markets in history—save for a couple of brief pauses—so it’s no surprise that passive investing has become the predominant philosophy over the last decade. If the volatility in U.S. equities continues in 2019, it would stand to reason that money would flow back into actively managed funds as investors try to improve their risk-adjusted returns.

Drilling Down

Let’s get to the second part of the equation—determining how active or passive you want to be in managing your specific allocations to various assets. This largely comes down to the asset in question.

Research has found that active managers are more likely to outperform their benchmark on a net-of-fee basis in certain asset classes. This is true in international equities, where the median active fund manager outperforms by over 1.5 percent per year. That’s a return well worth the fees of active management, and the same holds true in small-cap investing.

But there are some asset classes where the median manager can’t even beat the benchmark on a gross-of-fee basis. Add in fees on top of that, and active management becomes hard to justify.

Active fund manager performances don’t stay constant either. For example, Bank of America found that nearly half of U.S. large-cap equity fund managers outperformed their benchmarks in 2017, the best rate since 2009.  Keeping an eye on these trends—this is one area where advisors can help—can be the determining factor in what kind of approach you take for a specific asset in your portfolio.