Stablecoins

Stablecoins are digital tokens pegged to a reference currency (overwhelmingly USD) that function as the native unit of account and payment rail for the digital-asset economy. USD stablecoin supply grew to roughly $280–300B by year-end 2025 from ~$25B in 2020 — making stablecoins the single largest bridge between crypto rails and the dollar-denominated financial system. The GENIUS Act (enacted July 2025) established the first federal framework, but four implementation questions remain open — interest payments, monetary unity (singleness of money), illicit-finance prevention, and operational resilience — and will determine whether stablecoins become trusted payment instruments or stay confined to crypto trading.

The stablecoin market is structurally a duopoly. Tether (USDT) holds 65.6% share at ~$184B in supply — it dominates cross-border payment flows, emerging-market dollar access, and offshore crypto trading. Circle (USDC) holds 26.3% share at ~$60B, growing 73% year-over-year versus USDT's 36%, with a mandate to own the institutional and regulated segment. The GENIUS Act has defined stablecoins as two-tiered regulated instruments — the legislation will force every US-market issuer to be either a bank or a licensed payment stablecoin issuer with segregated reserves and third-party audits. Effective-date note: the Act's own text sets the deadline as the earlier of 18 months after enactment (= January 18, 2027) or 120 days after regulators finalize rules; a Morgan Lewis April 2026 status check (full-text verified 2026-07-22) states the "effective date: January 18, 2027" explicitly and reports that rulemaking was still incomplete across Treasury/FDIC/NCUA/OCC as of April 2026 — the KB's previously-recorded "November 2026" figure appears to assume regulators would finish early enough to trigger the 120-day alternative; both dates are legitimate readings of the same clause depending on when final regs land, so treat the effective date as January 2027 at the latest, possibly November 2026 if rulemaking finishes by ~July 2026 — not a settled single date. This is the most consequential regulatory moment for the sector since its creation.

The commercial model for fiat-backed stablecoins is straightforward: issuers hold customer dollars in short-term US Treasuries and money-market instruments, earning interest on the float while paying zero yield to stablecoin holders. At current rates, Tether generates substantial interest income on its $184B of reserve assets — making it one of the most profitable financial entities per employee globally. Circle's unit economics are complicated by a revenue-sharing agreement with Coinbase: Circle's 2024 prospectus disclosed $1.7B in revenue against just $167M operating income, with distribution costs exceeding $1B flowing predominantly to Coinbase.

Key Claims

• GENIUS Act signed July 18, 2025 — House passed July 17, 2025 (308-122); Senate 68-30. Creates a federal licensing regime for "payment stablecoins." Evidence: strong (Morgan Lewis)
• 1:1 reserve requirement, segregated accounts, monthly public reporting — All outstanding stablecoins must be backed by US dollars, demand deposits, or short-term Treasury obligations held in segregated accounts subject to regular third-party audits; rehypothecation and holder-interest payments are prohibited. Evidence: strong (Morgan Lewis)
• Effective date: January 18, 2027 (per Apr 2026 Morgan Lewis status check) — the earlier-of-18-months-or-120-days-post-final-rules clause; rulemaking across Treasury/FDIC/NCUA/OCC was still incomplete as of April 2026. Foreign issuers can serve the US market if Treasury certifies their home regime is "comparable." Evidence: strong, but see effective-date caveat above (Morgan Lewis implementation status)
• USDC supply ~$60B, growing 73% YoY — Circle NYSE IPO (CRCL) closed 2025. Evidence: moderate (Ledger Insights)
• Circle 2024 financials: $1.7B revenue, $167M operating income — distribution costs >$1B (predominantly to Coinbase) are "the massive dent" in profitability per the prospectus analysis; a late-2024 Binance deal carried a $74.1M upfront fee; Circle acquired Hashnote (tokenized money-market fund issuer). Evidence: moderate (pre-IPO prospectus analysis; article itself flags as partly paywalled) (Ledger Insights)
• USDT supply ~$184B, 65.6% market share — Tether remains private, opaque, Cayman-domiciled. Evidence: moderate (multiple sources)
• PayPal PYUSD and Stripe/Bridge entering — PYUSD is a third-tier issuer; Stripe acquired Bridge for stablecoin payment rails. Evidence: moderate (multiple sources)
• USD stablecoin supply ~$280B at year-end 2025, up from ~$25B in 2020 — an ~11x increase in five years. Evidence: moderate (Brookings — Liang & Dudley)
• Treasury Secretary Bessent projected stablecoins could reach $3 trillion by 2030. Evidence: weak (official projection) (Brookings)
• Four unresolved GENIUS implementation issues — interest payments, singleness/par of money, illicit-finance (BSA/AML), and operational resilience — frame the open regulatory agenda. Evidence: moderate (Brookings)
• Permissible reserve assets under GENIUS: US coin/currency, T-bills ≤93 days, uninsured bank deposits, and repo; issuers subject to the Bank Secrecy Act, with FinCEN to issue rules within 3 years. Evidence: moderate (Brookings)
• OCC conditionally granted national trust bank charters to Circle, Paxos + 3 others (Dec 2025) — an early signal of which issuers can operate federally. Evidence: moderate (Brookings)
• Enterprise adoption is early but inflecting: an EY survey found only 13% of firms currently use stablecoins, but >50% of non-users expect to adopt within 6–12 months; EY estimates stablecoins could be 5–10% of cross-border payments by 2030 ($2.1–4.2T). Evidence: weak (single survey) (Brookings)
• Total supply just under $300B; Tether 63% / ~$185B USDT; Ethena USDe >$14B (~3%) — adjusted stablecoin transaction volume reached $11.8T, +89% YoY in 2025. Evidence: moderate (The Block — Institutional Outlook)
• ~$300B stablecoin market cap across ~300M holder wallets, tracked alongside ~100 distinct stablecoins. Evidence: moderate (RWA.xyz)

Benchmarks & Data

• Total stablecoin market cap: ~$280–300B (year-end 2025 / 2026)
• USD stablecoin supply growth: ~$25B (2020) → ~$280B (end-2025)
• USDT: ~$184–185B (63–66% share)
• USDC: ~$60B (26.3% share, 73% YoY growth)
• Ethena USDe: >$14B (~3% share)
• Adjusted stablecoin tx volume: $11.8T (2025, +89% YoY)
• Stablecoin holder wallets: ~300M
• GENIUS Act prohibition effective: January 18, 2027 (backstop date; could be as early as ~Nov 2026 if regulators finish rulemaking sooner — see caveat)
• Circle 2024 revenue: $1.7B; operating income: $167M; distribution costs >$1B (mostly to Coinbase)
• Bessent projection: $3T by 2030

Open Questions

• Will Tether obtain a GENIUS Act license or restructure for non-US issuance only?
• How will PYUSD and Stripe/Bridge compete once the GENIUS Act licensing regime is live?
• What does the reserve-audit requirement reveal about Tether's actual asset composition?
• Will yield-bearing stablecoins (paying interest to holders) be permitted under GENIUS Act? (Brookings flags interest payments as the first of four unresolved issues.)
• Can the system preserve "singleness of money" (par convertibility across issuers) once multiple licensed stablecoins circulate?

Related Concepts

• On-Chain Settlement — Stablecoins are the primary unit used for on-chain settlement in institutional contexts
• Tokenization / RWA — Stablecoin reserve assets (Treasuries) are the same asset class being tokenized in the RWA market

Changelog

• 2026-06-15 — Initial compilation from 3 sources (GENIUS Act legislation, Circle IPO analysis, Morgan Lewis implementation)
• 2026-06-24 — Compiled new sources (genius-act-stablecoin-next-steps, rwa-tokenization-2026-state, institutional-crypto-outlook-2026)
• 2026-07-22 — Full-text fetch of genius-act-stablecoin-law-2025, genius-act-implementation-2026, circle-ipo-usdc-supply-2026 completed. Flagged an effective-date discrepancy (Nov 2026 vs the Jan 18, 2027 backstop date the Act's text actually specifies); added Circle's 2024 revenue/profitability detail from its pre-IPO prospectus