Crypto investors have flocked to the stablecoin in recent months, considering it to be a relatively safe haven during the turbulence of the U.S. regional banking crisis and a regulatory crackdown on crypto firms.

Tether's reserves include $53 billion of U.S. treasuries, the report said, up from $39.2 billion at the end of 2022. They also include $1.5 billion worth of bitcoin and $5.3 billion worth of loans which the report said are "over-collateralized".

In a post on its website, Tether said it has been seeking to "reduce its reliance on pure bank deposits" and leverage the repo market instead. A repo, short for repurchase agreement, refers to when financial institutions use U.S. Treasuries and other high-quality securities as collateral to raise cash, often overnight.

(Reporting by Elizabeth Howcroft and Hannah Lang; Editing by Alison Williams)