Circle said on Friday it has received ​a final regulatory ​approval from the U.S. Office of the ​Comptroller of the Currency to establish a national trust bank, sending the stablecoin giant's shares surging 10% in premarket trading.Here ‌are some ⁠details:⁠The charter allows Circle to act as custodian for its ​own reserves and hold crypto assets on behalf of institutional ​clients."OCC approval to establish Circle National Trust marks a defining step in bringing blockchain technology and digital assets into the core of the ⁠U.S. financial ‌system," Circle CEO Jeremy Allaire said in a statement.Circle said the approval places ⁠its trust bank under direct federal oversight ​by the OCC, the primary regulator for ​lenders and national trust banks.As regulatory hurdles eased, digital asset firms have expanded into traditional finance, pursuing banking licenses, custody businesses and payment services over the past year.Circle issues USDC, ‌a dollar-pegged stablecoin. Stablecoins are cryptocurrencies designed to maintain a fixed value, usually through a 1:1 peg to ⁠the U.S. dollar, and are widely used to transfer funds between crypto tokens.USDC has a market value ​of about $73.2 billion, according to CoinGecko.Circle shares have fallen 20.5% so far this year, through last close, giving it a market capitalization of about $15.7 billion, according to LSEG data.