The U.S. Commodity Futures Trading Commission (CFTC) has issued a warning to investors against cryptocurrency retirements accounts claiming to have received approval from regulators.

The CFTC explained that price volatility of cryptocurrencies is not reduced or limited “just because the virtual currencies are held in an individual retirement account, or IRA” and that advertisements using this kind of deceptive language should be viewed with caution. Importantly, it said that the Internal Revenue Service (IRS) does not approve or review investments for IRAs.

“Tax payers tend to focus on retirement savings more at tax time in order to increase deductions or maximize savings. As a result, some businesses may attempt to lure customers into buying highly volatile cryptocurrencies using false claims or by painting virtual currencies as less risky because they can be used for retirement saving,” the CFTC noted.

The CFTC particularly explained the risks associated with self-directed IRAs, which are held by trustees or custodians that permit investments in a broad array of assets, from virtual currencies, gold and other precious metals to real estate, promissory notes, or private placement securities.

“Custodians and trustees of self-directed IRAs may have limited duties to investors and generally will not evaluate the quality or legitimacy of an investment or its promoters,” it added. “While self-directed IRAs may offer investors a greater diversity of opportunities, alternative investments come with their own unique risks that retirement savers need to research and carefully consider.”