Hyperdrive is an AMM for fixed-rate yield on demand

Locking a token-denominated return against a variable vault

A saver uses a Hyperdrive long to exchange uncertain future vault yield for a bond-like claim with a known redemption amount at maturity. The quote fixes the return in the pool's base asset.

Suppose the base asset is DAI and the yield source is sDAI, the savings-vault token issued through Sky. An opening long pays DAI into the pool and receives a tokenized balance representing more face-value bonds than the current input. At maturity, those bonds redeem at 1:1 in base-asset terms. The spread between purchase price and face value supplies the fixed interest, while counterparties receive the variable sDAI yield. This structure fixes DAI units rather than their outside purchasing power. The next decision is choosing which yield source backs that claim.

Choosing a pool and preparing its base asset

Choosing a Hyperdrive pool starts with its base token, yield source, position duration and the network where its contracts are deployed.

Read the pool configuration before approving an asset. A pool connects one base token to one vault-shares token, then exposes its term and fee parameters on-chain. ERC-4626 integrations standardize share-to-base conversion, while direct adapters exist for Lido stETH, Rocket Pool rETH, Renzo ezETH, Aave and Morpho Blue. Match the asset held in the wallet to the accepted input and note whether settlement returns base or vault shares. An incompatible token address remains incompatible even when its ticker resembles the expected asset.

On Ethereum, chain ID 1 identifies mainnet. A contract address is 20 bytes and appears as 40 hexadecimal characters after 0x; a transaction hash is 32 bytes and displays 64 hexadecimal characters. DAI amounts use 18 decimal places, so an interface must scale wallet units correctly when building a transaction. These durable checks identify the intended pool and make its transaction receipt easier to verify.

Use this short decision checklist before the first approval or deposit:

• Base token: the wallet holds the exact ERC-20 asset that the pool accepts.
• Yield source: its returns come from a mechanism the user understands, such as Sky, Ethena, Lido, Aave or Morpho Blue.
• Term: the displayed position duration fits the date when liquidity will be needed.
• Depth: the quoted output remains acceptable for the intended trade size.
• Exit: holding to maturity remains workable if the early-close quote deteriorates.

How does Hyperdrive create a fresh term on demand?

Hyperdrive creates a fresh term by assigning every new position the pool's fixed duration from the start of its active checkpoint.

Published pool configurations include 91-day and 182-day position durations, while each individual pool fixes its own term before trading begins. A checkpoint groups positions opened during the same interval and records the vault share price used for their accounting. The contract backdates each position to that checkpoint's start, then adds the configured position duration to calculate maturity. Two trades in one checkpoint therefore share a maturity timestamp; trades in later checkpoints receive later dates without requiring a new expiring pool. The related mechanics are detailed in Using Hyperdrive.

That grouping makes terms available continuously while keeping maturity accounting finite, so the assigned date should match the holder's cash-flow horizon.

Flat+Curve turns elapsed time into a tradable price

Flat+Curve prices each Hyperdrive position by separating its matured portion from the portion that still carries rate exposure.

For a newly originated term, almost all exposure sits on the curve; checkpoint backdating creates a small already-matured slice after the interval begins. The YieldSpace-style invariant prices the curve portion from share reserves, virtual bond reserves and the configured time stretch. As time passes, more of the position becomes flat. That matured share moves toward a 1:1 base redemption while the remaining share still responds to the market fixed rate. An early close therefore combines accrued time value with a current curve quote rather than simply prorating the opening APR.

Even so, Hyperdrive's Solidity math normalizes APR over 365 days and stores fixed-point inputs with 18 decimal places, where 1e18 represents one. The curve benchmark uses normalized time 1 for a full term, while a fully matured component reaches time 0. Reserve depth and trade direction then determine the quote's price impact.

Long positions trade variable income for a fixed face value

A Hyperdrive long pays base into the pool and receives bonds whose face value exceeds their purchase price when the fixed rate is positive. Holding through maturity realizes that opening spread in base-asset units. Closing earlier sells the partially matured claim back through Flat+Curve, so the exit depends on remaining time, the new market fixed rate, fees and reserve depth. Lower market rates raise the value of an existing fixed claim; higher market rates reduce it. Longs therefore fit a dated liability better than an open-ended savings balance.

Short positions turn variable yield into rate exposure

A Hyperdrive short receives the underlying variable yield on capital supplied by LPs while committing to the fixed side of the bond trade.

The trader deposits the maximum loss required by the contract rather than borrowing an uncapped bond balance from an external lender. Hyperdrive invests the LP-funded capital in the yield source and accounts for the short's variable return. If realized variable yield exceeds the fixed obligation, the spread favors the short; if it falls short, the deposit absorbs the difference. The position doesn't use a liquidation threshold, though an early close still reacts to the current bond price and reserve-driven price impact.

Single-sided liquidity creates LP shares and delayed withdrawal claims

Liquidity providers in Hyperdrive supply one side rather than a base-and-bond pair, receive LP shares and support every maturity created by the pool.

Those LPs sit opposite traders: a long leaves LPs with variable-yield exposure, while a short leaves them with fixed-rate exposure. The pool also accrues trading fees and underlying yield on idle capital. Adding liquidity preserves present value per LP share, so a new deposit doesn't automatically receive value generated before entry. It can still take an immediate unrealized loss when the larger reserve base lowers the cost of closing existing positions, making the entry quote and active net exposure relevant checks.

Removing liquidity produces as many as two outputs: immediately available proceeds and withdrawal shares for capital still backing open positions. Hyperdrive accounts for withdrawal shares at a 1:1 relationship with active LP shares, then makes them redeemable as positions close and idle capital returns. Ready claims receive proceeds through the withdrawal pool, and a redemption processes only the amount currently funded. An LP deciding when to exit therefore watches both LP share price and withdrawal-share readiness.

Underlying assets and exit timing define the risk boundary

The Hyperdrive risk boundary includes its base asset, yield source, pool integration and the chain that settles each trade.

An ERC-4626 pool relies on four familiar vault actions - deposit, mint, withdraw and redeem - yet the vault's strategy still determines whether share value rises or falls. Direct integrations such as stETH, rETH, ezETH and Morpho Blue add their own accounting and liquidity conditions. A long held to maturity fixes the bond's redemption amount in base units; it doesn't fix the base asset's outside-market value. Shorts face variable-yield underperformance, early exits face rate movement and LPs face delayed capital through withdrawal shares. Pool review should therefore follow the exact yield source and settlement asset, as explained in Hyperdrive about networks.

On-chain configuration exposes fees and integration limits

On those terms, Hyperdrive exposes fee, duration, reserve and circuit-breaker parameters on-chain, letting traders and integrators inspect the rules before submitting a transaction.

The fee structure has four fields: curve, flat, governance LP and governance zombie. The curve fee applies to the rate-sensitive part of a trade, while the annualized flat fee applies to the matured part. Governance receives configured portions of LP fees and post-maturity interest rather than a separate universal surcharge. Realized trading cost also includes reserve-driven price impact, so the useful quote is the final output amount alongside the APR.

The published contract code identifies version v1.1.0 and uses Solidity syntax compatible from 0.8.20 up to the 0.9.0 boundary. A full deployment uses five target contracts because EIP-170 limits one contract's runtime code to 24,576 bytes. This sharding changes how integrators resolve function targets, while the IHyperdrive interface remains the entry point. Read-only calls expose pool configuration, pool information, checkpoints, withdrawal readiness and base-to-share conversion.

Internally, rate math uses 256-bit unsigned values and an 18-decimal scale. The LP share-proceeds routine caps its Newton-style solve at four iterations, with explicit tolerances for safe completion. These are implementation constants rather than trading promises; an integrator still derives transaction limits from the selected pool's live configuration before building calldata.

Pendle, Notional and Spectra use different term structures

Pendle, Notional and Spectra are established alternatives when the deciding factor is how maturities and yield claims are organized.

Pendle and Spectra split yield-bearing assets into Principal Tokens and Yield Tokens, then route fixed-yield demand through Principal Token pricing. Notional represents fixed lending and borrowing with fCash markets at scheduled maturities. Hyperdrive keeps long, short and LP accounting inside a pool that issues terms on demand. Pendle or Spectra fit strategies that require separate principal and yield claims, Notional provides explicit fixed-credit markets and Hyperdrive provides continuous term origination from one liquidity base.