Ethena USDe: a synthetic dollar that turned into a credit book
Data as of 31 Aug 2026.
Bottom line. The mechanism isn't broken — it's working right now, and that's exactly the problem. With funding around 10% annualised and 79% of days positive over the past year, sUSDe pays 4.2% on a 30-day average against 3.83% on 3-month T-bills. A 37 bp spread is what top-of-cycle looks like, not a temporary dip. In its current form, the yield doesn't compensate for the risk.
What it is
A synthetic dollar that, until 2026, earned the perp basis (long spot, short perp). It has since been rebuilt into a credit portfolio wrapped in a stablecoin.
Findings
1. The engine has been almost entirely swapped out
The basis trade — the reason anyone bought this — is 13.3% of backing. The rest is DeFi lending, institutional loans, liquid stables and RWAs.
Ethena dashboard, Backing Assets, 31 Aug 2026 17:00. Red is the part the product was built around.
The credit sleeve is 43.1% (DeFi lending plus institutional loans). In August it picked up a billion dollars in a separate Cayman vehicle alongside FalconX — roughly a quarter of total supply (CoinDesk, 19 Aug 2026). The risk has moved from funding rates into credit and duration.
2. Nearly half the backing is stuff you can buy directly
Liquid stables (31.1%) plus RWAs (12.3%) = 43.4%. A sUSDe holder carries smart-contract, exchange-counterparty and credit risk on a portfolio that is almost half repackaged cash and Treasuries. And those liquid stables yield 4.1% — 27 bp over the risk-free rate.
3. The yield doesn't pay for the risk
sUSDe — Ethena dashboard, Market Data, 31 Aug 2026. T-bills — TradingEconomics, 31 Aug 2026.
Ethena publishes this spread on its own dashboard: through August it ranged from 0.00% to 1.80%, with some days at zero premium. In 84.6% of weeks the yield came in under 5%.
4. The protocol isn't betting on its own engine
Funding is running at 9.99% annualised across venues, 79% of days over the past year were positive, and Ethena holds only 0.78% of BTC open interest ($28.8bn). There's plenty of room to scale the trade — yet the basis is held at 13.3% and a third of the book is parked in stables at 4.1% (Ethena dashboard, Market Data, 31 Aug 2026). The team is looking at the same funding rate and doesn't trust it enough to lean in.
5. One event, two prints — both true
October 2025: USDe printed $0.65 on Binance (−35%), while at the protocol level backing held and the price never went below $0.97. Both are correct: Binance had no direct mint/redeem access, so arb couldn't close the gap. The lesson isn't the number, it's the plumbing — peg resilience on any venue is set by redemption infrastructure, not by collateral quality.
What would change the call
| When | What to pull | Thesis survives if |
|---|---|---|
| 30 Sep and 31 Oct 2026 | 30-day sUSDe yield and 3M T-bill rate — same day, two sources | spread ≥ 200 bp on both dates |
| 1 Oct 2026 | reserve fund in absolute terms (not %, which flatters while supply shrinks) | reserve above $62.08m |
| 15 Oct 2026 | basis share of backing; whether a report on the Cayman vehicle (borrowers, collateral coverage) exists | basis ≥ 30% and the report exists |
| 15 Dec 2026 | equity-basis share and 30-day yield | equity basis ≥ 25% with yield ≥ 8% — the engine has genuinely restarted |
For reference: a $62.08m reserve against $4.12bn supply is 1.51% — above the usual stress line for a delta-neutral stable (reserve under $50m with supply over $3bn). Proof of reserves dated 28 Aug 2026 came from three independent attestors.
Calls, kept separate from the conclusion
- By 15 Dec 2026, equity basis will not reach 25% of backing with a 30-day yield of 8% or higher. Checkable on Ethena's Backing Assets and Market Data pages. If wrong, the engine really has restarted and this needs a fresh look.
- By 31 Oct 2026, the sUSDe–3M T-bill spread will not exceed 200 bp on a 30-day average.
Unknowns
Obtainable:
- What's inside the Cayman vehicle — borrowers, collateral coverage, tenors, rates. Without it, there's no way to say what backs a quarter of supply. Route: a governance-forum request or FalconX directly.
- Institutional loan rates are published as a "4–7%" range rather than a figure — no precise number for 11.9% of the book.
Unknown to anyone:
- How much capital equity perps can absorb before the premium compresses. The 14–17.5% rates exist precisely because the short side is empty. Nobody knows the capacity, Ethena included — it lists this as a risk itself.
- How the structure behaves in a credit event. Every stress it has survived — October 2025, the Bybit hack in February 2025 — was about funding and exchange counterparties. There has been no credit event with the new backing mix. Sample size: zero.
Takeaway
At 37 bp of premium, there's nothing to be paid for. And this isn't a cyclical trough — conditions for the basis trade are already favourable, so this is the outcome under good conditions. The picture changes only if the T-bill spread holds ≥ 200 bp for two consecutive months, or equity and commodity basis reach ≥ 25% of the book at ≥ 8% yield.
Research for information only. Not investment advice.