GMX vs Ostium: the same machine pointed at different assets

GMX is mostly crypto, with at least 8 non-crypto markets (5 commodity, 2 ETF and 1 equity). Ostium is mostly everything that is not: metals and energy, equity indices, FX, equities and ETFs, with some crypto attached. Because the mechanism and the order semantics are nearly identical, moving between them is the least disruptive switch in the routed set. Because the asset classes mostly are not, the decision is made largely by what you want exposure to.

Four things, and each of them changes how you trade. Price comes from an oracle, not from matched orders, so there is no depth to read and no spread to work. Your counterparty is a pool rather than another trader, so you are paying its liquidity providers for the capital you are using. Order size is a USD notional and collateral is derived by dividing by leverage. And a limit order is a trigger against the oracle rather than a resting bid, so it cannot be traded against and it cannot earn you a maker rebate. Anyone arriving from Hyperliquid or Lighter should read that list as the set of habits to drop.

GMX returned 110 distinct markets across its two deployments: 108 on Arbitrum and 12 on Avalanche, 10 of them on both chains, served by 138 GM pools. GMX's 110 markets are not all crypto: 93 are crypto by our catalog's column, at least 8 are non-crypto (BRENTOIL, GOLD, NATGAS, SILVER and WTIOIL as commodity markets, QQQ and SPY as ETF markets and SPCX as an equity market), two are on tokenized gold (XAUT.v2 and XAUt0), and 7 (BONK, CVX, FLOKI and four more) are tickers our catalog does not carry or prices as a different instrument. The tokenized-gold tickers are XAUT.v2 on Arbitrum and XAUt0 on Avalanche, ERC-20s tracking the metal rather than commodity perps, and our own catalog files them as crypto for that reason. Ostium publishes no readable market list, so its inventory here is what our own gateway routes, labelled as first-party for that reason. Of the 71 Ostium markets our gateway routes, as read on 8 September 2026, 35 are equities, 8 are ETFs, 7 are commodities (gold, silver, platinum, palladium, copper, WTI crude and Brent crude), 7 are equity indices (the S&P 500, the Nasdaq 100, the Dow Jones, the DAX, the FTSE 100, the Nikkei 225 and the Hang Seng), 4 are dollar FX pairs (AUD/USD, EUR/USD, GBP/USD and NZD/USD), 9 are crypto and one (USD/KRW) we could not classify. Read against our catalog and each venue's own marks, the non-crypto instruments on both Ostium and GMX are gold, silver, WTI crude and Brent crude among the commodities; beyond those the overlap is crypto.

• GMX: 110 markets on Arbitrum and Avalanche, 138 GM pools behind them, with at least 8 non-crypto markets (5 commodity, 2 ETF and 1 equity)
• Ostium: 71 markets in our gateway, metals and energy, equity indices, FX, equities and ETFs, plus crypto
• What Ostium had to itself among the indices was the Dow Jones (DJI), the DAX (DAX), the FTSE 100 (FTSE), the Nikkei 225 (NIK) and the Hang Seng (HSI), as read on 8 September 2026; the S&P 500 and the Nasdaq 100 also trade on Lighter, as US500 and US100.

GMX's crypto book never closes and has no reopen. Its synthetic non-crypto markets (BRENTOIL, GOLD, NATGAS, QQQ, SILVER, SPCX, SPY and WTIOIL) track underlyings that do keep sessions, so treat those as you would an Ostium market and check each one. Ostium tracks instruments with real sessions. Metals and FX run nearly around the clock on weekdays with maintenance breaks and close over the weekend; index and equity markets keep exchange hours. Two things follow. A stop on an Ostium index position cannot protect you across a closed session, because the price you reopen at is the price the underlying reopened at. And any oracle-priced market carries gap risk in proportion to how long it was shut, which for a Friday-to-Monday index position is the whole weekend. GMX's crypto book has no equivalent exposure. This is the single most important practical difference between two venues that otherwise behave the same way.

GMX charges a fee to open and to close, applies a price impact that helps or hurts depending on whether your trade balances the pool or skews it further, and then bills a borrowing fee per hour the position is open. Ostium charges to open and then charges a rollover to keep the position, plus the oracle spread on entry. Both therefore make holding cost money in a way an order-book venue with a flat schedule does not. Neither publishes rates in an API we can read, so no figure appears here for either. The right way to compare them is to price your intended holding period on both before you open, not to look for the lower entry fee.

Because both accept size as a USD notional and derive collateral the same way, the same order body is valid on both. That sounds convenient and it is the reason a routing mistake between these two does not error. A misresolved symbol sent to the wrong one of the pair opens a real position, at the right size, in the wrong asset class, and reports success. Our gateway resolves symbols per venue before dispatch specifically so that this cannot happen from the app. If you are integrating both directly, pin the venue at the same place you pin the symbol.

Hypertradeworx routes to GMX and Ostium from the same order ticket and the same self-custodial wallet, alongside Hyperliquid, Lighter and AsterDex. Both are on Arbitrum, so funding one funds the other, and positions from both land in one portfolio. Margin still does not cross: each venue collateralises its own positions and liquidates them on its own logic.