Stablecoins are sold as a payments upgrade. In reality, they are a bid for the banking system’s cheapest funding.
The headline version: Stablecoins are not mainly about faster payments. They are about capturing the idle balances — current accounts, payroll buffers, merchant floats, treasury operating cash — that banks have relied on for decades as cheap, sticky funding. Once a deposit becomes a token backed by T-bills and repo, the interest economics leave the banking system. That is why this fight has turned political so fast.
The numbers that matter
Stablecoins are ~$315 billion against ~$19 trillion in U.S. bank deposits. Small today. But the migration forecasts are not small:
- Standard Chartered (Jan 2026): ~$500B could leave U.S. bank deposits by end of 2028. Regional banks most exposed.
- Citi (Sep 2025, revised): $1.9T base case / $4T bull case by 2030.
- Government stress scenario: $6.6T in deposit displacement under high-adoption assumptions — enough to trigger a Senate fight over whether stablecoins can pay yield at all.
Those are funding-base numbers, not payments numbers.
How the capture works
User converts bank money → stablecoin issued against reserve assets (bills, repo, cash) → user holds token in a wallet/app that looks like a bank interface → balance sheet has changed. What was a bank liability is now a token liability. Interest income follows.
Even “non-interest-bearing” stablecoins are economically powerful — the reserve portfolio throws off yield. The market recreates savings-like economics through distributor rewards, fee rebates, treasury sweeps and reserve-sharing arrangements.
The knife fight in Washington: Can stablecoins behave like deposits without being regulated like banks?
The card play: Stablecoins don’t need to replace Visa/Mastercard. They just sit behind them. Hold value in stablecoins, spend anywhere cards are accepted. The acceptance layer stays. The money underneath migrates.
Retail makes headlines. Corporate treasury moves real float.
What the regulators are saying
ECB (March 2026 working paper): Stablecoin adoption measurably correlated with declining retail deposits and reduced lending to firms. Banks lose cheap funding → rely on more expensive wholesale funding → shrink credit supply.
Bank of England: Proposals for holding limits and reserve structures that deliberately restrain stablecoin scaling.
U.S. GENIUS Act: Who can issue? What backs them? What happens in a run? Who gets the yield? These are monetary architecture questions, not startup questions.
Banks are not worried that a better payments app might nibble a fee line. They are worried that a new class of cash-like instrument might siphon off low-cost liabilities while leaving banks with higher funding costs and the same capital burden. That is not whining. That is algebra.
The incumbents’ moves
Mastercard: $1.8B acquisition of BVNK (March 2026) — connecting stablecoins to fiat rails across 130 countries. Preserve the interface, change the liability.
Fiserv: FIUSD stablecoin built on Paxos/Circle, integrated into 10,000 FI clients and 6M merchant locations. Stablecoins as a standard option inside bank-adjacent software.
Circle/Tether: Making reserves look boring enough for mainstream finance. Reserve transparency, government money-market structures, blue-chip custodians.
Banks: Tokenised deposits — keep money as a bank liability but add on-chain programmability. The counter-move.
Everyone suddenly has a view on monetary design. Funny how fast that happens when the revenue pool is large enough.
The risks created by success
BIS research: Stablecoin flows move short-dated Treasury yields by 2.5–3.5bp normally, 5–8bp when bills are scarce. That is a macro variable, not a crypto curiosity.
FX angle: Majority of net stablecoin inflows come from non-USD currencies. This is also an offshore dollar story with geopolitical edges.
Concentration: A handful of issuers and distribution points control most of the market. That is not decentralisation. It is a new form of monetary concentration wearing a more fashionable jacket.
The fork
Path A — Constrained: Tightly regulated, low-yield payment instruments. Growth continues but slower, more institutional, more contained.
Path B — Open: Reward structures stay open, card acceptance expands, treasury adoption accelerates, stablecoins collapse into familiar interfaces. Straight contest over the ownership of the idle dollar.
The old line was that stablecoins threatened SWIFT. That was always too shallow.
The real threat is simpler and more serious: stablecoins threaten deposits. And deposits are where power lives.
Omar Al-Bakri builds AI systems for financial services. Previously 15 years in enterprise FinTech sales across Tier 1 banks and payments infrastructure.
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