Currency Pair

CurrencyPair represents a spot or cash market quoted as BASE/QUOTE. The base currency is the asset being bought or sold, and the quote currency prices one unit of the base. Nautilus uses this type for fiat FX pairs and crypto spot pairs.

Examples include EUR/USD.SIM, BTCUSDT.BINANCE, and ETH/USD.KRAKEN.

Fields

Field	Type	Required/default	Notes
`instrument_id`	`InstrumentId`	Required	Stored as `id` in Rust.
`raw_symbol`	`Symbol`	Required	Native venue symbol.
`base_currency`	`Currency`	Required	Asset bought or sold.
`quote_currency`	`Currency`	Required	Currency used to price the base asset.
`price_precision`	`u8`	Required	Decimal places allowed for prices.
`size_precision`	`u8`	Required	Decimal places allowed for order sizes.
`price_increment`	`Price`	Required	Smallest valid price step.
`size_increment`	`Quantity`	Required	Smallest valid size step.
`ts_event`	`UnixNanos`	Required	Event timestamp in nanoseconds.
`ts_init`	`UnixNanos`	Required	Initialization timestamp in nanoseconds.
`multiplier`	`Quantity`	`1`	Contract multiplier.
`lot_size`	`Option<Quantity>`	`None`	Rounded lot or board size.
`max_quantity`	`Option<Quantity>`	`None`	Maximum order quantity.
`min_quantity`	`Option<Quantity>`	`None`	Minimum order quantity.
`max_notional`	`Option<Money>`	`None`	Maximum order notional value.
`min_notional`	`Option<Money>`	`None`	Minimum order notional value.
`max_price`	`Option<Price>`	`None`	Maximum valid quote or order price.
`min_price`	`Option<Price>`	`None`	Minimum valid quote or order price.
`margin_init`	`Option<Decimal>`	`0`	Initial margin rate.
`margin_maint`	`Option<Decimal>`	`0`	Maintenance margin rate.
`maker_fee`	`Option<Decimal>`	`0`	Maker fee rate. Negative values rebate.
`taker_fee`	`Option<Decimal>`	`0`	Taker fee rate. Negative values rebate.
`tick_scheme`	`Option<Ustr>`	`None`	Registered variable tick scheme name.
`info`	`Option<Params>`	`None`	Adapter metadata.

</Tab> <Tab value="Python">

Field	Type	Required/default	Notes
`instrument_id`	`InstrumentId`	Required
`raw_symbol`	`Symbol`	Required	Native venue symbol.
`base_currency`	`Currency`	Required	Asset bought or sold.
`quote_currency`	`Currency`	Required	Currency used to price the base asset.
`price_precision`	`int`	Required	Decimal places allowed for prices.
`size_precision`	`int`	Required	Decimal places allowed for order sizes.
`price_increment`	`Price`	Required	Smallest valid price step.
`size_increment`	`Quantity`	Required	Smallest valid size step.
`ts_event`	`int`	Required	Event timestamp in nanoseconds.
`ts_init`	`int`	Required	Initialization timestamp in nanoseconds.
`multiplier`	`Quantity`	`1`	Contract multiplier.
`lot_size`	`Quantity \| None`	`None`	Rounded lot or board size.
`max_quantity`	`Quantity \| None`	`None`	Maximum order quantity.
`min_quantity`	`Quantity \| None`	`None`	Minimum order quantity.
`max_notional`	`Money \| None`	`None`	Maximum order notional value.
`min_notional`	`Money \| None`	`None`	Minimum order notional value.
`max_price`	`Price \| None`	`None`	Maximum valid quote or order price.
`min_price`	`Price \| None`	`None`	Minimum valid quote or order price.
`margin_init`	`Decimal \| None`	`0`	Initial margin rate.
`margin_maint`	`Decimal \| None`	`0`	Maintenance margin rate.
`maker_fee`	`Decimal \| None`	`0`	Maker fee rate. Negative values rebate.
`taker_fee`	`Decimal \| None`	`0`	Taker fee rate. Negative values rebate.
`tick_scheme`	`str \| None`	`None`	Registered variable tick scheme name.
`info`	`dict \| None`	`None`	Adapter metadata.

</Tab> </Tabs>

Note: Python constructors use instrument_id; Rust stores the same value as id.

Behavior

CurrencyPair has instrument class Spot.
It has no expiration, strike price, option kind, or derivative underlying field.
It is never inverse. The settlement currency and cost currency are the quote currency.
Use this type for both fiat FX pairs and crypto spot pairs.

:::warning Do not model dated futures, swaps, or options as CurrencyPair only because their symbols look like pairs. Use the specific derivative type so cost currency, settlement currency, expiration, and notional calculations match the venue. :::

Example

rust

use nautilus_core::UnixNanos;
use nautilus_model::{
    identifiers::{InstrumentId, Symbol},
    instruments::{CurrencyPair, InstrumentAny},
    types::{Currency, Money, Price, Quantity},
};
use rust_decimal_macros::dec;

let btcusdt = CurrencyPair::builder()
    .instrument_id(InstrumentId::from("BTCUSDT.BINANCE"))
    .raw_symbol(Symbol::from("BTCUSDT"))
    .base_currency(Currency::from("BTC"))
    .quote_currency(Currency::from("USDT"))
    .price_precision(2)
    .size_precision(6)
    .price_increment(Price::from("0.01"))
    .size_increment(Quantity::from("0.000001"))
    .min_quantity(Quantity::from("0.000001"))
    .min_notional(Money::from("10.00 USDT"))
    .max_price(Price::from("1000000.00"))
    .min_price(Price::from("0.01"))
    .margin_init(dec!(0.001))
    .margin_maint(dec!(0.001))
    .maker_fee(dec!(0.001))
    .taker_fee(dec!(0.001))
    .ts_event(UnixNanos::default())
    .ts_init(UnixNanos::default())
    .build()
    .unwrap();

let instrument = InstrumentAny::CurrencyPair(btcusdt);

python

from decimal import Decimal

from nautilus_trader.model import Currency
from nautilus_trader.model import CurrencyPair
from nautilus_trader.model import InstrumentId
from nautilus_trader.model import Money
from nautilus_trader.model import Price
from nautilus_trader.model import Quantity
from nautilus_trader.model import Symbol

BTC = Currency.from_str("BTC")
USDT = Currency.from_str("USDT")

btcusdt = CurrencyPair(
    instrument_id=InstrumentId.from_str("BTCUSDT.BINANCE"),
    raw_symbol=Symbol("BTCUSDT"),
    base_currency=BTC,
    quote_currency=USDT,
    price_precision=2,
    size_precision=6,
    price_increment=Price.from_str("0.01"),
    size_increment=Quantity.from_str("0.000001"),
    ts_event=0,
    ts_init=0,
    min_quantity=Quantity.from_str("0.000001"),
    min_notional=Money(10.00, USDT),
    max_price=Price.from_str("1000000.00"),
    min_price=Price.from_str("0.01"),
    margin_init=Decimal("0.001"),
    margin_maint=Decimal("0.001"),
    maker_fee=Decimal("0.001"),
    taker_fee=Decimal("0.001"),
)

Adapters

Representative adapters that create or consume CurrencyPair instruments include:

Binance for spot markets.
Kraken for spot markets.
OKX for spot markets.
Tardis for spot metadata.
Interactive Brokers for FX cash contracts.
Hyperliquid for spot assets.

Data explains market data that references instruments.
Execution explains order checks that use instrument precision.
Value types explains Price, Quantity, and Money.

Currency Pair

Currency Pair

Fields

Behavior

Example

Adapters

Related guides