A bumper year for US stocks helped boost America’s 401(k)s, IRAs, and brokerage accounts. But for Americans with a high-deductible healthcare plan (HDHP), their biggest portfolio win might have been in their health savings account (HSA). With tax-deductible contributions, tax-deferred growth like a Roth IRA, and tax-free withdrawals, HSAs offer a rare “triple tax advantage.” And with a catchphrase like that, HSA demand has been steadily rising, rewarding the industry’s leader.

• America’s top HSA administrator, HealthEquityHQY
  , anticipates that 1.1M new HSA accounts will be opened in FY 2024, which wraps Jan. 31 — with its total estimated HSAs expected to hit 9.8M accounts.
• HQY
  rose over 40% last year on the newfound demand for healthcare-oriented saving and investing, fueled by the boom in new accounts — with 20%+ year-over-year revenue growth in its latest quarter.

The Robinhood of healthcare investing: HSAs, which don’t get as much buzz as retirement accounts, are used by about 13% of eligible Americans — with more than $30B in assets on HealthEquity’s platform. The enterprise also offers custodial services — allowing companies, healthcare providers, and other brokerages to provide HSA accounts to their users. That leaves lots of room for growth, which will reward the industry’s far-away leader.