The Stablecoin Ledger: How Bank-Issued Tokens Are Repricing the Cost of Credit

On August 28, the Bank for International Settlements' chief, Pablo Hernández de Cos, issued a warning that stablecoins could make borrowing more expensive. That's not a forecast; it's a balance-sheet arithmetic. The stablecoin market now holds roughly $304 billion, with Tether at $183 billion and USDC at $74 billion. Federal Reserve researchers call these tokens potential competitors to traditional transaction accounts. The ledger doesn't lie: banks are being forced to respond. Banks are expanding into digital money. A Federal Reserve survey from September 2025 found half of respondents prioritizing stablecoin or digital-asset growth over three years. But the technology is not monolithic. J.P. Morgan's JPM Coin represents a bank deposit on a blockchain. Société Générale-FORGE's CoinVertible is a MiCA-regulated stablecoin backed by segregated collateral. Different promises, different liabilities. Nitin Gaur, Head of Institutions at Nethermind, puts it plainly: "The interesting question stopped being whether a bank can issue and became what a bank is issuing." A tokenized deposit remains bank funding. A stablecoin under the US GENIUS Act requires one-to-one backing with eligible reserves—cash or short-dated Treasuries. The Treasury proposed implementation rules on August 17. The balance-sheet impact is where the data gets cold. When a corporate treasurer moves $100 million from a demand deposit into the bank's own stablecoin, the bank converts a funding source into a matched, non-lendable reserve pool. Gaur explains: "A stablecoin issued under a GENIUS pathway is not a deposit. It is a payment instrument backed by segregated reserves the issuer cannot lend against." That's a direct hit to the bank's lending capacity. The wider effect depends on where those reserves end up. If they stay within the banking system, they can still provide funding—but more concentrated and quicker to leave. Adrian Wall, Managing Director of the Digital Sovereignty Alliance, identifies the risk: "If stablecoin adoption ultimately shifts funding away from bank deposits rather than recycling those funds back into the banking system, banks could face higher funding costs and potentially less capacity to extend credit." The market is already testing this. In July, Citi reported a dollar payment from London to Thailand over a US holiday weekend using its tokenized-deposit service. Western Union launched USDPT in May, with Anchorage Digital Bank issuing the stablecoin on Solana. J.P. Morgan reports around $7 billion in daily activity across Kinexys products. CoinVertible reported €156.6 million of euro tokens and $12.55 million of dollar tokens outstanding on August 31. These figures measure different things—transaction volume versus circulating supply—so they don't tell us which model is winning. But they tell us the volume is real. The fragmentation problem is next. If every bank issues its own token, you get dozens of thin, incompatible pools. Europe's Qivalis has assembled 37 banks across 15 countries around a planned euro stablecoin, targeting launch in H2 2026. Ernesto Olmedo Pereira, Head of Strategy & DeFi at Qivalis, says sharing the currency is deliberate: "If every bank launches its own token, you get dozens of thin, incompatible pools instead of one deep, liquid euro instrument." That's a rational response to a coordination failure. But it doesn't solve the core issue: the shared coin still sits on the liability side, and the reserves still sit in a segregated pool. The conventional narrative is that stablecoins will drain deposits and raise funding costs. That's a correlation, not a causation. The data suggests the outcome depends on reserve recycling. If stablecoin reserves are deposited back into the banking system—as many are, via money market funds or bank deposits—the net effect on funding is neutral. The real risk is concentration and velocity. In my 2020 DeFi yield audits, I saw how stablecoin flows shifted liquidity pools in hours. The same logic applies to bank balance sheets. A $100 million demand deposit is sticky; a $100 million stablecoin reserve is a hot potato. The question isn't whether stablecoins replace deposits—it's whether they replace them with something more volatile. That's the ghost in the machine. Forensic data reveals the ghost in the machine. The next signal to watch is not the stablecoin market cap. It's the deposit flow data from the banks themselves. If Qivalis launches and the euro stablecoin attracts real corporate treasury flows, we'll see the funding cost curve shift. The ledger will show it. When the market screams, the data whispers. Banks that ignore the balance-sheet arithmetic will find their lending margins compressed. The ones that treat stablecoins as a product, not a threat, will survive. The rest will be audited.