The DOL guidance threatens that employers and investment firms could be subject to investigation and enforcement actions should they allow individuals using brokerage windows to invest in cryptocurrency, according to Senator Tuberville.

He also introduced another crypto-related bill, the Prohibiting Foreign Adversary Interference in Cryptocurrency Markets Act, which would prohibit the Commodity Futures Trading Commission from registering a digital commodity platform that is owned in whole or in part by an entity organized or established in China.

Back in 2022, following the DOL’s warning to fiduciaries, Sen. Tuberville introduced the legislation that would prohibit the DOL from limiting the types of investments that workers can invest in through their brokerage accounts, including 401(k)s. In addition, a San Francisco-based retirement plan provider filed a lawsuit against the DOL over its crypto warning.

The Financial Freedom Act would prohibit the DOL “from constraining the range or type of investments that may be offered to participants and beneficiaries of individual retirement accounts who exercise control over the assets in such accounts,” according to a Tuberville statement.

Related: Bitcoin in your 401(k)? New bill would boost alternative assets in retirement plans

While President Trump has vowed to make the U.S. the "crypto capital of the planet," cryptocurrency assets make up only a small part of 401(k)s, according to the government watchdog, Government Accountability Office.

Crypto assets in 401(k) plans do have uniquely high volatility and their returns can come with “considerable risk,” according to the GAO report, 401(k) Plans: Industry Data Show Low Participant Use of Crypto Assets Although DOL's Data Limitations Persist, however, cryptocurrencies only encompass less than 1% of defined contribution plans.