Fidelity’s new research parses the active versus passive debate a bit further.

By applying two filters — fund cost, and the size of the fund family managing an active fund — Fidelity found the average U.S. large-cap active fund outperformed benchmarks by 70 basis points in 2015, after accounting for fees.

Between 1992 and 2015, the same subset of active funds outperformed the passive competition by 18 basis points annually, as the average passively managed large-cap U.S. equity fund underperformed benchmarks by 4 basis points annually.

“Industry-wide averages can be misleading, and may be doing investors a disservice by giving them the perception that all active funds cannot outperform passive funds, which is simply not true,” said Timothy Cohen, chief investment officer for Fidelity Investments, in a statement.

How much of a disservice? Assuming the 18 basis point return of filtered active funds — those with lower fees that come from the largest fund families — Fidelity says workers could retire with $64,000 more than they would had they invested in passive funds, assuming annual investments of $5,000 over 40 years.

“Applying certain straightforward and objective filters can be a helpful starting point for investors seeking to identify above-average actively managed equity funds that beat benchmarks,” said Cohen.

To maintain that objectivity, Fidelity compared active and passive U.S. large-cap equity funds with expense ratios in the respective lowest quartile, which was capped at 79 basis points for active funds, and 11 basis points for passive funds, according to funds costs in 2015.

When filtering for size of fund family, Fidelity focused on total assets under management for firms running active and passive funds.

In terms of active management, size matters, concludes Fidelity. Larger fund companies “use size to their advantage by committing more resources to research and trading, and the benefits of those resources can be shared across all the companies’ active U.S. large-cap funds,” according to language in Fidelity’s report.

At the end of 2015, the median amount of funds managed by all U.S. large-cap active managers was about $243 million. The median amount managed by the top five fund families by size was more than $180 billion.

The five largest fund families held about 49 percent of all actively managed assets, according to Fidelity.

“Any average analysis of the entire industry will include a high proportion of active fund families that may lack comparable resources to compete,” the report says.

In fact, Fidelity says the average low-cost active fund from the largest five fund families outperformed the industry average of active funds 98 percent of the time since 1994, when accounting for three year average returns.

A Fidelity representative explained that data on both fees and the five largest fund families was rebalanced on a monthly basis over the research period — 1992 to 2015 — to account for changes in data.

At the end of 2015, the five largest active fund families were Fidelity, American Funds, Vanguard, T.Rowe Price, and JP Morgan.

At the beginning of the research period, the top five fund families were Fidelity, American Funds, Vanguard, Invesco, and American Century.