When your HSA account balance reaches $500, you can choose to invest any funds in your account over that amount in one or more available investment funds. Any earnings on the funds in your HSA are distributed tax-free if used to cover eligible health care expenses now or at any time in the future. Note that investment funds may fluctuate with market conditions and that past performance is no indication of future results. It is possible that the market value of your HSA will decrease.
See the HSA Investment options.