Schwab Corp. is preparing to build out its own tax-aware long-short products as the firm’s customers have piled into the strategy beloved by millionaires looking to cut their tax bills.

Schwab is looking at offering an extended version of its current direct-indexing capability on long-short accounts, Chief Executive Officer Rick Wurster said on an earnings call with analysts Thursday. The appeal for Schwab is that more direct control over the offering results in balance-sheet and operational efficiencies, he said.

“It’s a way we can deliver sustainable long-short strategies to our clients in a way that is operationally and financially manageable over the longer term,” Wurster said. His comments come after the firm, which provides custody for such strategies, recently tightened its limits for customers wishing to access them.

Tax-loss harvesting strategies have grown so rapidly that regulators are getting worried. The Internal Revenue Service issued an array of warnings to Wall Street last month saying it plans to publish guidance and may take other steps to bar certain trades that money managers are using to help clients harvest losses and lower tax bills, including on ordinary income.

Among them was a long-short strategy popularized by AQR Capital Management, the world’s largest hedge fund.

In recent months, Schwab has raised its minimums for clients wanting to access long-short tax-aware strategies on its platform, among other changes. In early September, the brokerage told clients they would have to have a minimum of $10 million of assets to fund some long-short separately managed accounts, an increase from $1 million. The firm also said it won’t enroll new clients or accept new funds in portfolio margin accounts, which use greater leverage.