Lighter vs Ostium: a zero-fee book against oracle-priced real-world perps

Lighter is an order book with no trading fee, mostly crypto, with at least 55 non-crypto markets (34 equity, 9 commodity, 5 ETF, 5 FX and 2 index) attached. Ostium is oracle-priced real-world perps on Arbitrum: metals and energy, equity indices, FX, equities and ETFs, plus a crypto set. The overlap is much wider than the roundups suggest, and wider than a symbol list alone reveals. Read against our catalog and each venue's own marks, the non-crypto instruments on both Ostium and Lighter are gold, silver, platinum, palladium, copper, WTI crude and Brent crude among the commodities, AUD/USD, EUR/USD, GBP/USD and NZD/USD among the FX pairs, the S&P 500 and the Nasdaq 100 among the indices, 23 equities and two ETFs; beyond those the overlap is 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. What Lighter has is a book instead of a pool, and no fee to trade it.

Lighter is a zk-rollup order book: your counterparty is another trader, your fill comes from resting liquidity, and you can post limits into the book and read the depth you are trading against. Ostium prices from oracle feeds and puts a liquidity pool on the other side, which is the mechanism that makes an on-chain gold or index perp possible at all. The consequence that matters day to day is what moves your position. On Lighter it takes a trade. On Ostium the oracle updating is enough, so a gap in the underlying reprices you without anyone transacting.

Lighter reported 244 order books with 226 active, split 216 perpetual and 10 spot. Ostium is the one venue in the routed set that publishes no market list we can read without querying an indexer, so its inventory here is what our own gateway routes rather than a list from Ostium, and it is labelled as a first-party number for that reason. What sits in those markets is the point rather than the count. 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. Ostium's own price feed carried 94 pairs on the same day, so the venue's book is wider than what we route.

• Lighter: 226 active books, 216 perp and 10 spot, all reporting zero fees
• Ostium: 71 markets in our gateway in September 2026, metals and energy, equity indices, FX, equities and ETFs, plus crypto
• Lighter's non-crypto books, from our catalog's asset-class column price-checked against Lighter's own marks: at least 34 equity, 9 commodity, 5 ETF, 5 FX and 2 index, the metals being XAU, XAG, XPT, XPD and XCU and the indices US500 (S&P 500) and US100 (Nasdaq 100)

The usual claim is that Lighter is crypto plus a few stocks and Ostium is everything else. Reading Lighter's own book against our catalog's asset-class column says otherwise: at least 34 equity, 9 commodity, 5 ETF, 5 FX and 2 index non-crypto books. The commodity set is BRENTOIL, NATGAS, WHEAT, WTI, XAG, XAU, XCU, XPD and XPT, the FX set is AUDUSD, EURUSD, GBPUSD, NZDUSD and USDJPY, and the index books are US500 (S&P 500, marking around 7,692) and US100 (Nasdaq 100, marking around 29,584). Read against our catalog and each venue's own marks, the non-crypto instruments on both Ostium and Lighter are gold, silver, platinum, palladium, copper, WTI crude and Brent crude among the commodities, AUD/USD, EUR/USD, GBP/USD and NZD/USD among the FX pairs, the S&P 500 and the Nasdaq 100 among the indices, 23 equities and two ETFs; beyond those the overlap is crypto. Read that with a caveat or two, worth more than the count itself. It is a floor rather than a total: the same column still files active Lighter books like SAMSUNGUSD, XIAOMI and MRNA as crypto. And symbol matching alone is not enough to read either venue's list, because Lighter also runs a book called SPX that is SPX6900, a memecoin under a dollar, not the index. What differs inside the overlap is the machine: on Lighter you trade at a price in the book against another trader and pay no fee, on Ostium at the oracle price against a pool and pay to open and to hold.

Lighter's own order-book endpoint reported a maker fee and a taker fee of exactly zero on all 226 active books, which makes the zero the live venue configuration rather than a promotion somebody wrote about. Ostium charges to open a position and then charges to keep it, plus whatever the oracle spread costs you on entry. No Ostium rate is quoted here, because it is not readable from an API we can call. Zero fee is also not zero cost on Lighter: funding between longs and shorts applies there like anywhere else, and on a position held for weeks funding will dwarf the trading fee you did not pay.

Crypto perps never close, so Lighter behaves the same at 03:00 on a Sunday as it does mid-week. Ostium tracks instruments with sessions behind them. Metals and FX run nearly around the clock on weekdays and close for the weekend; equity and index markets keep exchange hours. That means weekend gap risk is a genuine consideration on an Ostium index position and does not exist on a Lighter crypto book. Lighter equity perps track an underlying with a session too, so check the specific book rather than assuming the whole venue is 24/7.

Two USD numbers that mean opposite things. Ostium takes order size as a USD notional and derives your collateral by dividing by leverage. In our own app the Lighter path does the reverse: it takes USD collateral and derives the asset size as collateral multiplied by leverage and divided by price. Same currency in the field, inverted meaning, and the error scales with leverage: put a notional into the collateral field at 10x and you get a position ten times the one you wanted. Our gateway and app normalise this before dispatch. If you are integrating either venue yourself, this is the detail to test first.

Hypertradeworx routes to Lighter and Ostium from one order ticket and one self-custodial wallet, alongside Hyperliquid, AsterDex and GMX, converts the size conventions above, and shows positions from both in a single portfolio. Margin stays where the position is: Lighter collateral cannot back an Ostium trade, because each venue runs its own risk engine and liquidation logic.