> For the complete documentation index, see [llms.txt](https://docs.nexus.xyz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.nexus.xyz/trading/trading/perpetuals/market-specifications.md).
# Market Specifications
Contract specifications for every listed perpetual — tick and lot size, margin rates, open-interest caps, funding, and fees.
Contract specifications for every perpetual market listed on the Nexus Exchange. Every value below is a per-market parameter the venue is configured with, not a platform-wide constant — a market's tick size, margin rates, funding cap, and position limits are set when it is listed and tuned between release gates.
### Instruments
| Instrument | Description | Underlying | Settlement | Trading hours |
| --------------- | ----------------------------------------------------------- | --------------- | ---------- | ---------------- |
| `BTC-USDX-PERP` | Bitcoin, the largest crypto asset by market capitalization. | BTC / USD index | USDX | 24/7, continuous |
| `ETH-USDX-PERP` | Ether, the native asset of the Ethereum network. | ETH / USD index | USDX | 24/7, continuous |
| `SOL-USDX-PERP` | Solana, the native asset of the Solana network. | SOL / USD index | USDX | 24/7, continuous |
All markets are quoted, margined, and settled in [USDX](/overview/usdx.md), and trade continuously — there are no session breaks, daily settlement windows, or expiries. The underlying is an external index price, not the last trade on the Nexus book; see [Price Oracles](/trading/trading/perpetuals/price-oracles.md) for how the index is constructed and how stale feeds are handled.
### Order and price increments
| Instrument | Tick size | Lot size | Minimum order size | Maximum order size |
| --------------- | --------- | --------- | ------------------ | ------------------ |
| `BTC-USDX-PERP` | 0.5 USDX | 0.001 BTC | 0.001 BTC | 100 BTC |
| `ETH-USDX-PERP` | 0.10 USDX | 0.01 ETH | 0.01 ETH | 1,000 ETH |
| `SOL-USDX-PERP` | 0.01 USDX | 0.1 SOL | 0.1 SOL | 10,000 SOL |
**Tick size** is the smallest price increment an order may be priced at. **Lot size** is the smallest quantity increment. An order is rejected if its price is not a whole multiple of the tick size, if its quantity is not a whole multiple of the lot size, or if its quantity falls outside the minimum/maximum bounds. See [Order Types](/trading/trading/perpetuals/order-types.md).
### Margin and position limits
| Instrument | Initial margin rate | Maintenance margin rate | Open-interest cap |
| --------------- | ------------------- | ----------------------- | ----------------- |
| `BTC-USDX-PERP` | 2% | 1% | 10,000 BTC |
| `ETH-USDX-PERP` | 2% | 1% | 50,000 ETH |
| `SOL-USDX-PERP` | 5% | 2.5% | 200,000 SOL |
**Initial margin rate** is the fraction of position notional your account equity must cover to open a position; **maintenance margin rate** is the fraction it must keep to avoid liquidation. Margin is whole-account cross margin — your entire USDX balance backs every open position. See [Margining](/trading/trading/perpetuals/margining.md) and [Liquidations](/trading/trading/perpetuals/liquidations.md).
**Open interest is capped per market.** The cap bounds the total size of all open positions on one side of a market. Once a market is at its cap, orders that would increase open interest are rejected; orders that reduce it — closing or reducing an existing position — continue to be accepted. The cap is a venue risk control, not a per-account limit.
### Funding
| Instrument | Funding interval | Premium sampling | Funding-rate cap |
| --------------- | ---------------- | ---------------- | ---------------- |
| `BTC-USDX-PERP` | Hourly | Every 60s | 0.1% |
| `ETH-USDX-PERP` | Hourly | Every 60s | 0.1% |
| `SOL-USDX-PERP` | Hourly | Every 60s | 0.1% |
Funding settles at the interval above, with the mark/index premium sampled at the sampling interval and time-weighted across the period. The rate paid in any one interval is clamped to the funding-rate cap in both directions. See [Funding Rates](/trading/trading/perpetuals/funding-rates.md).
### Fees
| Instrument | Maker | Taker |
| --------------- | ------------ | ----- |
| `BTC-USDX-PERP` | 2 bps rebate | 5 bps |
| `ETH-USDX-PERP` | 2 bps rebate | 5 bps |
| `SOL-USDX-PERP` | 2 bps rebate | 5 bps |
Maker rebates are credited and taker fees charged on filled notional. This is the venue's base tier; query the schedule in effect for your account at any time via `GET /account/fees`. See [Exchange REST](/apis-and-rates/apis-and-rates/exchange-rest.md).
***
Generated from the per-market config home, the configuration the exchange and oracle services boot from. Cross-checked against the venue's public `GET /markets` response of 2026-09-08. Where the two disagree, the difference is stated at the top of this page; an undocumented disagreement is a bug — the page is regenerated and diffed on every change to a market's configuration.
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