Ostium: perpetual trading, Gateway and vault access

Ostium offers perpetual exposure to crypto and traditional markets through contracts on Arbitrum, using USDC for collateral and settlement. Users take long and short positions without buying the underlying asset. Leverage, carrying costs and liquidation affect those positions.[2]

The main website now leads with Gateway by Ostium, an API service for professional traders, institutions and embedded trading businesses. It still links the core trading interface. These are related access routes with different onboarding and commercial contexts; the public protocol tariff should not be assumed to be a complete institutional integration agreement.[1]

The current market list totals 75 pairs; an older welcome-page card still says 71. The pair list is used here for coverage. Available leverage is a ceiling, not a recommended position size, and may differ between intraday and overnight trading.[3][2]

Crypto and stock contracts use a dynamic spread that responds to short-term directional flow; other groups use standard bid/ask execution. A balanced-flow zero-spread description is not a fixed zero-cost promise.[10]

Adding collateral lowers effective leverage; removing it raises leverage and is limited by the position’s minimum margin. TP and SL levels can be adjusted without a separate adjustment charge. The position guide conflicts on whether an omitted TP applies an automatic cap or leaves the trade open. Its shorthand should not be used as a reliable uncapped-profit rule; the accepted order parameters need to be checked.[8]

Stock day trades have a separate clock: the documented window is 9:35 a.m.–3:45 p.m. Eastern Time. Positions above the pair’s overnight leverage ceiling automatically close at 3:45 p.m. at the available market price. Positions within that ceiling may remain open. The cutoff is not an optional reminder, and closing-market slippage still matters.[12]

For an illustrative 8,000-USDC crypto opening-fee basis, 0.10% equals 8 USDC. This is an entry commission calculation, excluding oracle charges, spread, carrying cost and any builder fee. Fees reduce the collateral that backs the final position.[7]

Rollover accrues per block on every market. Rates update daily at 00:00 UTC and combine underlying carry with a typically 1%–2% annual premium. One direction may receive a credit; crypto rollover is not simply a zero-sum payment between Ostium longs and shorts. The live Net Rate for the chosen side is needed for a holding estimate.[6]

Profitable closes within 15 seconds incur an additional fee: 40 × (15 − elapsed seconds) ÷ 15 basis points on notional, capped at realised profit. Losing or breakeven closes, and closes at or after 15 seconds, avoid that fee. At eight seconds, a 7,500-USDC notional gives a 14-USDC charge if profit is at least 14 USDC; a lower profit caps the charge.[6]

The oracle charge is 0.10 USDC per request, with a 10-USDC transaction cap. Failed opens can consume it even when collateral returns. It is separate from network gas and is not a percentage of the trade.[6]

The closure guide says a successful full close refunds the opening oracle charge; a partial close costs another 0.10 USDC and must leave a valid remaining position. Automated TP/SL execution has no oracle charge. After the early-close condition is excluded, the guide does not add a routine percentage exit commission. Net proceeds still reflect entry cost, price movement, spread and accumulated rollover.[9]

An integration can add a builder fee. The SDK preview separates protocol opening, oracle and builder charges, then reports effective collateral and exposure after those costs. Its output also distinguishes maker and taker components. The fixed reference table is therefore a description of published protocol rates, not a binding quote for every routed transaction.[26]

Trading does not require a hosted exchange cash balance: uncommitted USDC stays in the wallet, while opened-position collateral enters the trading contracts and returns with settled PnL after closure. The funding guide does not establish a direct bank-deposit or fiat-withdrawal account. Wrong-network transfers are not ordinary pending deposits that support can simply reverse.[5]

Email-created smart accounts use sponsored trading gas; external Web3 wallets generally require ETH for gas. The account guide describes reserving or deducting 2 USDC for future withdrawal gas. This is a funding provision for that account route, not a universal 2-USDC fee on every protocol withdrawal.[4]

Vault redemption is separate from closing a trade. OLP withdrawal requests lock the selected tokens and stop their fee earnings. Settlement typically takes two to three days, but the contract sets a dynamic delay. Conversion uses the settlement-day OLP price, after which a separate Redeem action releases USDC. Cancellation is possible before settlement; settled redemption has no stated expiry. The upgrade cancelled older pending requests and returned their OLP, so affected holders need a new request.[15]

Wallet control does not make committed margin or vault capital freely transferable. The protocol settles open exposure under its contract rules. Liquidation occurs automatically without a margin call, even while the user is offline, and the remaining collateral is retained. There is no assurance that a warning or support reply will arrive before the threshold is crossed.[11]

The liquidation threshold depends on chosen leverage relative to the pair maximum. In the published approximation, a 20x position on a 200x-maximum pair reaches the threshold at a 97.5% collateral loss, equivalent to roughly a 4.875% adverse price move before fees. Accrued costs bring liquidation closer; the actual position’s current liquidation price is the relevant figure.[11]

The published audit index lists reviews by Zellic, ThreeSigma and Pashov across 2024–2026. It describes a January 2026 high-severity share-accounting finding as resolved before the subsequent launch. Those are Ostium’s summaries of dated, scoped reviews; they do not establish that every current contract, upgrade or external dependency is free of defects. The same documentation links contract addresses and the responsible-disclosure programme.[17]

Ostium’s recovery terms document an OLP exploit on 15 July 2026 and the associated trading pause. Eligible losses are fixed at the snapshot. Claims up to 1,000 USDC use a convenience class; larger holders may irrevocably reduce their claim to 1,000 within 30 days of portal launch. Convenience claims expire after 90 days; the portal supplies the actual dates. Other recoveries depend on available funds, without guaranteed amount or timing. Screening applies. The first acceptance signature releases broad incident-related claims; automatic recording alone does not. Remaining vault assets are handled separately. These are recovery terms, not a statement that a claim window remains open or that losses have been repaid.[20]

The current vault design puts a junior buffer ahead of OLP in its financial loss waterfall and uses off-chain hedging with daily reconciliation. That mechanism is a description of normal settlement exposure, not protection against every exploit. Ostium expressly says OLP is uninsured. If losses exhaust the buffer and reach OLP, the vault blocks new deposits and reflects the loss at settlement.[14]

The interface terms require users to be at least 18 and exclude people residing in, citizens of, entities organised in, or people located in the United States, United Kingdom, European Union and Philippines, alongside sanctioned jurisdictions. Circumventing restrictions with a VPN is prohibited. A wallet connection does not establish legal eligibility.[19]

The privacy policy covers IP and device information, wallet addresses, signing-related public data, transaction signatures and login analytics. It allows international processing and variable retention for service, legal and dispute purposes. Privacy requests can seek access, correction or deletion, subject to applicable limits and identity checks. The policy does not establish a universal retention period or promise to erase public-chain records.[18]

The trading overview says users can manage positions through compatible contract interactions rather than relying exclusively on the front end. This is a technical alternative, not a staffed telephone close-out service. Network, oracle or protocol failures can still prevent execution; an email requesting closure is not itself an on-chain order.[2]

The main terms start disputes with written notice: 20 days to respond, a meeting within 45 days after sending, and 90 days for initial resolution. They combine Cayman governing-law/court wording with Delaware JAMS arbitration. The recovery plan has separate dispute terms.[19]

No exact financial-authorisation record for the interface providers or protocol was established. Their terms describe software interfaces and expressly deny acting as an exchange operator, execution provider or clearing house. This profile’s exchange-directory category describes the trading protocol; it is not a representation that either named company holds an exchange licence.[19]

The Nasdaq subscriber agreement concerns use of market data. It distinguishes personal non-professional use from internal professional use and restricts redistribution. A market-data arrangement does not confer permission to serve a restricted jurisdiction or mean that Nasdaq guarantees protocol execution. Its separate contractual terms should not be mistaken for custody protection.[21]

The privacy policy names Ostium Foundation and Ostium Labs Co. The recovery document identifies the foundation as a Cayman exempted foundation company. A separate incorporation jurisdiction for Labs was not established in the inspected material; Cayman governing-law wording is not enough to infer it.[18][20]

The Gateway homepage reports more than USD 53 billion of cumulative notional matched and settled. That is a company-reported cumulative activity measure, not annual revenue, customer assets or current daily turnover. Its professional-facing presentation coexists with the linked trading interface; this does not create a second exchange identity for duplicate-coverage purposes.[1]

The retrieved public trading page displayed an Online label and links to trading, points, vault and portfolio functions. This supports an active public interface at the source check, while leaving account availability, transaction completion and post-incident recoveries untested.[27]

Operator

Ostium Foundation and Ostium Labs Co.; interface providers for the protocol

Exchange model

Decentralised

Service scope

Arbitrum perpetual contracts settled in USDC, with a separate liquidity vault.

Client types

Retail clients; Professional clients; Institutional clients

Pricing publication

Public and quoted pricing

Other names

Gateway by Ostium

Pricing scope

Public protocol charges; integration fees, market impact and variable carry affect executable costs.

Funding scope

USDC on Arbitrum, directly or through documented third-party conversion and bridge routes.

Custody and asset handling

Wallet-signed trading; committed margin and OLP deposits follow smart-contract settlement and withdrawal rules.

Client eligibility

Adults only; the interface excludes the United States, United Kingdom, European Union, Philippines and sanctioned jurisdictions.

Support

Discord, published email contacts and a separate security disclosure programme.

Authorisation and registration scope

No exact financial-authorisation record was established for the interface providers or protocol.

Exchange metadata checked 20 Oct 2026Source 1Source 2Source 5Source 13Source 14Source 18Source 19Source 20Source 26Source 27

OLP deposits use a request-and-settle process. USDC waits for the daily 00:00 UTC settlement, converts at that settlement price, and then requires a Redeem action to obtain the tokens. Pending deposits can be cancelled before settlement. New locked deposits are no longer offered; existing lock NFTs retain their original expiry and must be redeemed before the ordinary withdrawal process. A pending deposit, a pending redemption and a spendable wallet balance are different states.[16]

The current vault overview allocates 30% of opening fees to OLP, with that share adjustable. It says rollover fees and trader PnL are not direct OLP yield sources under the upgraded design. Its historical pre-upgrade APR range should therefore not be quoted as a current return. Vault TVL, total USDC in the vault and broader protocol TVL also measure different things.[14]

Ostium’s data API exposes prices, depth, candles and market status without authentication at the documented check. Rate limits apply by IP and route and are signalled through response headers. Public data access does not authorise trading, and production Arbitrum and testnet order hosts must not be mixed. A missing API login requirement is not evidence of unrestricted write permissions.[22]

In delegated execution, the trader owns the USDC and positions while an authorised delegate signs and pays gas for actions. Initial setup requires USDC approval and registration of that delegate. This is substantive transaction authority, not merely access to price data. The documentation does not establish an exchange-style menu of separate read, trade and withdrawal API-key permissions.[23]

The delegate guide documents trader-signed registration and revocation, including a transaction built explicitly from the trader account. Closing a browser or disconnecting a front end should not be assumed to revoke an on-chain delegation. Revoking authority is also distinct from closing existing positions or cancelling outstanding orders; those need their relevant actions and confirmed state.[24]

Gateway advertises an MCP connection for AI trading agents. That is integration capability, not a documented discretionary advisory service or a promise of profitable automation. The user or integrating business must still understand which signing authority the agent has received.[1]

The fill-history method can query a time range and return transaction hashes, position identifiers, prices, size, fees and realised PnL. This can support reconciliation of executions, partial closes and liquidations. It does not by itself establish a complete tax return, fiat acquisition history or a guarantee that every external wallet transaction is included.[25]

Pre-trade previews check collateral, pair leverage, minimum position size, exposure caps and market hours. They can change between calculation and submission. Separate calculation helpers accept accrued costs when estimating liquidation and PnL; using a default zero carrying cost for an older position can overstate its remaining margin.[26][28]