The Stablecoin Map: From Simple Pegs to the Infrastructure Layer of Finance

Stablecoins started as a workaround - a way to stay in crypto without riding the volatility. They've become something more fundamental: the settlement medium of a new financial system. Understanding them requires understanding that "stablecoin" covers at least four genuinely different mechanisms with very different risk profiles.

Fiat-backed (the dominant model)

USDC and USDT are fiat-backed: every token in circulation is backed by a dollar (or equivalent) held in a bank account or money-market fund. The issuer holds the reserves; the token represents a claim on them.

USDT (Tether): ~$145-185B in circulation as of mid-2026, dominant on Tron ($82B) and Ethereum. Settled $7.9 trillion in volume in 2025 - more than Visa processed globally. The reserve transparency question has haunted Tether for years; their attestations are improving but still not full audits. Issuer can blacklist addresses and freeze balances - a centralization risk that's abstract until it isn't.

USDC (Circle): ~$73.6B as of June 2026. More transparent reserve disclosures, monthly attestations from Grant Thornton, regulated in multiple jurisdictions. Native on 34+ chains via CCTP (burn-and-mint, not wrapped), which is a meaningful technical advantage for cross-chain use.

OUSD (Open Standard): announced June 30, 2026 - a 140+ partner consortium (Visa, Stripe, Coinbase, BlackRock, Google, Solana, Aptos, Stellar) that returns nearly all reserve yield to distribution partners. If it ships as designed, it rewrites the economics of stablecoin distribution. Not live yet as of writing.

Crypto-collateralized (the decentralized attempt)

DAI/USDS (MakerDAO/Sky): backed by a basket of crypto collateral (ETH, stETH, RWA) with overcollateralization - you need to lock $1.50 of ETH to mint $1 of DAI. The protocol liquidates positions automatically if collateral value drops below threshold. The system is transparent and governance-minimized, but the peg is only as stable as the collateral base during a market crash.

Yield-bearing (the new category)

sDAI/sUSDS: Maker's savings-rate variants. Deposit DAI, receive an interest-bearing receipt. The DSR rate is governance-set; historically 4-8%.

sUSDe (Ethena): delta-neutral synthetic dollar. Ethena holds spot ETH and shorts ETH perpetuals - delta cancels, yield comes from the funding rate on the short. Works exceptionally well when funding is positive (which it usually is in bull markets). Carries significant risk when funding goes negative.

USDY (Ondo): backed by short-duration US Treasuries. ~5.3% APY historically. Explicitly structured as a regulated security in the US - not a stablecoin for regulatory purposes. Important distinction.

Algorithmic (the cautionary tale)

UST/LUNA collapsed in May 2022, destroying ~$60B in value in days. The mechanism: UST was minted by burning LUNA, and LUNA was minted by burning UST, creating a reflexive relationship that worked in growth phases and death-spiraled when confidence broke. The lesson - not that algorithmic stablecoins are impossible, but that any mechanism that requires growth to maintain stability will fail when growth stops.

The payments stack

For agent systems and cross-chain payments, three things matter about stablecoins beyond their peg mechanism:

1. Finality and cost: Tron USDT settles in ~10 seconds for $0.0003-0.01. Ethereum USDC settles in ~12 seconds for $2-15. Solana USDC settles in <1 second for $0.00025. The choice of stablecoin and chain is a cost decision.

1. Bridge/transfer mechanism: USDC moves cross-chain via CCTP (burn-and-mint, lowest trust). USDT moves via USDT0 (LayerZero OFT). Other stablecoins use various bridge standards with varying security models.

1. Issuer freeze risk: Both USDC and USDT can be frozen at the address level by their issuers. Over $500M in USDT was frozen in a single 30-day window in 2026. For agent systems holding significant balances, this is a systemic risk worth managing through diversification and position limits.

At Morca Labs, we model each stablecoin in Botanary's adapter registry as a risk-scored asset with freeze risk, depeg probability, bridge trust level, and securities classification - because the settlement medium is part of the risk model, not a neutral abstraction.