Pooled parlay market making

Prediction market liquidity vault: be the house without running it.

Purrdict's testnet liquidity vault pools USDC and competes as a market maker for prediction-market parlays. Depositors share the maker-side gains and losses through an ERC-4626 vault share, subject to utilization limits, settlement risk, and real drawdowns.

Executable vault currently HyperEVM Testnet only · no guaranteed return · test USDC

Reviewed August 3, 2026 · Purrdict Research

A prediction market liquidity vault is pooled collateral that takes the market-maker side of trades. In Purrdict's parlay design, the pool posts the “house” collateral, collects the pot when a taker's combination loses, and pays out when every required leg wins. Depositors own transferable vault shares whose value follows the pool's accounted net assets.

01 / The model

A depositor-owned house book

Every parlay needs a counterparty. If a taker stakes $100 at a quoted 5.0× total payout, somebody must stand ready to contribute the other $400. The Purrdict vault can be that counterparty. It participates in the same request-for-quote auction as other makers and wins only when its quote is selected.

The pool is not a passive wrapper around a fixed interest rate. It is an active risk book. Automated pricing estimates the joint probability and correlation of the selected outcomes, then decides whether the proposed payout compensates the pool for taking the other side.

Taker losesIf any required leg loses, the pool receives its collateral back plus the taker's stake.
Taker winsIf every required leg wins, the taker receives the full pot and the pool loses its posted collateral.
Voided onlyIf a combination is voided without a losing leg, both sides receive their escrowed collateral back.
Open accessDepositors can join the pooled book without operating a quoting server or settlement keeper.
02 / Economics

Where the house edge comes from

Suppose the true probability of a three-leg combination is 18%. Fair payout before costs is roughly 5.56×. If the pool quotes 5.0× and a taker stakes $100, the pool locks $400. It earns $100 when the taker loses and loses $400 when the taker wins.

At the assumed probability, expected value is 0.82 × $100 − 0.18 × $400 = $10. That $10 is a modelled expectation across many comparable trades—not the result of any individual parlay and not a promised return. A short run of taker wins can easily overwhelm the quoted edge.

The quality of the pool's pricing matters more than the slogan. Stale outcome prices, hidden correlation, concentrated exposure, or sharp takers can turn an apparent edge into a loss.

03 / Ownership

Deposits become mpMV vault shares

The testnet pool follows the ERC-4626 vault pattern. A depositor supplies test USDC and receives mpMV shares representing a proportional claim on idle cash, collateral locked behind live parlays, and settled credits that have not yet been swept.

Share value uses accounted net asset value rather than continuous mark-to-market pricing. Live positions are carried at their locked collateral, so the pool's value can step up or down when a parlay settles. A favorable-looking open book can still resolve against the pool.

Redemption depends on idle liquidity. Funds already committed to a live parlay remain in escrow until settlement or a timeout path releases them. A depositor may be able to redeem part of a position immediately while waiting for the remainder.

04 / Guardrails

Risk caps are enforced at fill time

The current testnet contracts enforce three limits atomically when a quote fills. These values can change, so the live venue API—not this page—is the source of truth for current parameters.

80% utilizationCurrent aggregate collateral budget; at least 20% of accounted pool value remains outside live positions.
$50,000 per parlayCurrent maximum maker collateral that one combination can lock.
64 live positionsCurrent ceiling on concurrently backed parlays.
Bounded quoting keyOnly the vault's registered, expiring signer can authorize a price on the pool's behalf.

When capacity is exhausted, the vault stops bidding. The limits reduce the size and concentration of potential losses; they do not make losses impossible.

05 / Risk

“Be the house” still means taking risk

  • Variance. Several winning takers can cause a large drawdown even when the pricing model has positive expected value.
  • Model and correlation risk. A quote that treats related legs as independent can materially underprice the payout.
  • Liquidity timing. High utilization can delay a complete redemption until positions settle.
  • Oracle and dispute risk. Every payout depends on the underlying outcome resolution and the venue's dispute rules.
  • Smart-contract and operational risk. Contract defects, signing-key failures, or keeper failures can affect the pool despite its caps.
  • Deployment risk. The current system uses test contracts and test USDC. Testnet behavior does not establish mainnet safety.
06 / Product status

What is live today?

HyperEVM Testnet, chain ID 998

The mpMV vault, Parlay v2 escrow, gasless deposit and redemption flow, RFQ quoting, and settlement lifecycle are operational with test USDC. Mainnet deposits and executable mainnet Purrdict parlays are not live.

Contract addresses can rotate during testnet development. The venue's GET /v1/vault response is authoritative for the current vault, escrow, token addresses, utilization, and per-parlay cap.

07 / Evidence

Standards and methodology

Vault mechanics and current limits are reviewed against Purrdict's deployed testnet contracts and venue API. General claims about vault shares, inventory risk, and parlay pricing are grounded in the relevant tokenized-vault standard and current prediction-market research.

08 / FAQ

Prediction market vault FAQ

What is a prediction market liquidity vault?

A prediction market liquidity vault pools depositor collateral and uses it to quote or back trades. Purrdict's testnet vault acts as the maker side of multi-leg prediction market parlays.

What does ‘be the house’ mean?

It means taking the market-maker side of parlay trades through a shared pool. The pool collects the taker's stake when any required leg loses and pays its posted collateral when every required leg wins.

Is vault return guaranteed?

No. Pricing edge is an expectation, not a guarantee. Winning takers, poor pricing, correlation mistakes, smart-contract failures, oracle failures, and illiquidity can all reduce the share value.

Can depositors withdraw at any time?

Redemptions are limited by idle liquidity. Collateral backing unresolved parlays cannot be withdrawn until those positions settle or time out, so a full redemption may need to wait.

Is the Purrdict parlay vault on mainnet?

No. The current mpMV vault, escrow, RFQ flow, and test USDC are deployed on HyperEVM Testnet, chain ID 998. They are not a mainnet investment product.