It can be frustrating to find a top-performing fund, only to learn it’s closed to new investors. According to Morningstar data that is cited in an article in Barron’s, there are 278 closed funds, but only a few of them are worth trying to sneak into, such as T. Rowe Price’s Capital Appreciation fund, which manages $50 billion and has outperformed 99% of its Moderate Allocation fund counterparts for 15 years with a 9.5% annualized return, and has been closed since 2014.

Many closed funds have a backdoor entrance that investors can sidle through; in T. Rowe’s case, that backdoor allows investors with more than $250,000 invested—either at the firm or with other families, stocks and ETFs—to buy into their closed funds through their Summit Program. A similar rule applies to the Artisan International Value fund, which has also beaten 99% of its peers for 15 years. Investors should always reach out to a closed fund’s firm directly to find out the rules and how to possibly circumvent them, the article advises. Another backdoor could be through a financial advisor who could have access to an institutional share class that is still open. And at larger fund companies, routes through advisory and retirement-plan pathways are usually left open, like the Fidelity Growth Company which has officially been closed since 2006 but allows new investors through those channels.

But many of the top-performing funds operated by boutique management firms, especially small- and micro-cap stock funds, have a much more narrow backdoor, because they tend to focus on niche areas where skilled managers pick the right stocks to beat the indexes. These kinds of funds are often “hard closed”—meaning no one gets in except new investors in retirement plans. However, some funds have a bit more flexibility, such as the Lord Abbett Micro Cap Growth which allows existing investors in addition to retirement-plan participants and employees, to continue purchasing shares. And sometimes an existing shareholder of a closed fund can buy a share from an outside broker and then transfer it to you without the fund manager’s knowledge, which you can then add to your position. “Even in the strictest limited offering of a fund, if you find someone who owns it and transfers a share, that’s the one way around closure,” an anonymous fund rep told Barron’s.

For investors who absolutely can’t get into the fund they want, the alternative is to search for a substitute that functions in a similar fashion or is managed by the same manager. T. Rowe Price submitted a filing to launch an ETF called the Capital Appreciation Equity ETF, headed by the same manager as the closed fund, David Giroux. Though a launch date hasn’t been announced, when it opens investors would get the chance to access Giroux’s selections. The ETF will hold 100 stocks. Of course, for some investors there’s no substitute, especially for a phenomenal fund such as the Invenomic Fund which has trounced its peers with an annualized 27.3% return over the last 5 years. But high fees and exclusive access to existing shareholders, advisors and retirement-plan participants have kept everyone else out.