Binary Option

BinaryOption represents a binary outcome instrument that settles to a fixed payoff based on whether a condition is true. It can model prediction markets, binary options, or venue-specific yes/no contracts.

Examples include prediction market outcomes and binary event contracts.

Fields

Field	Rust type	Python type	Required/default	Notes
`instrument_id`	`InstrumentId`	`InstrumentId`	Required	Stored as `id` in Rust.
`raw_symbol`	`Symbol`	`Symbol`	Required	Native venue symbol.
`asset_class`	`AssetClass`	`AssetClass`	Required	Asset class of the outcome market.
`currency`	`Currency`	`Currency`	Required	Quote and settlement currency.
`activation_ns`	`UnixNanos`	`int`	Required	Contract activation timestamp.
`expiration_ns`	`UnixNanos`	`int`	Required	Contract expiration timestamp.
`price_precision`	`u8`	`int`	Required	Decimal places allowed for prices.
`size_precision`	`u8`	`int`	Required	Decimal places allowed for order sizes.
`price_increment`	`Price`	`Price`	Required	Smallest valid price step.
`size_increment`	`Quantity`	`Quantity`	Required	Smallest valid size step.
`outcome`	`Option<Ustr>`	`str \| None`	`None`	Outcome label when the venue provides it.
`description`	`Option<Ustr>`	`str \| None`	`None`	Human‑readable market description.
`max_quantity`	`Option<Quantity>`	`Quantity \| None`	`None`	Maximum order quantity.
`min_quantity`	`Option<Quantity>`	`Quantity \| None`	`None`	Minimum order quantity.
`max_notional`	`Option<Money>`	N/A	Rust only	Maximum order notional value.
`min_notional`	`Option<Money>`	N/A	Rust only	Minimum order notional value.
`max_price`	`Option<Price>`	N/A	Rust only	Maximum valid quote or order price.
`min_price`	`Option<Price>`	N/A	Rust only	Minimum valid quote or order price.
`margin_init`	`Option<Decimal>`	N/A	Rust only	Initial margin rate.
`margin_maint`	`Option<Decimal>`	N/A	Rust only	Maintenance margin rate.
`maker_fee`	`Option<Decimal>`	`Decimal \| None`	`0`	Maker fee rate. Negative values rebate.
`taker_fee`	`Option<Decimal>`	`Decimal \| None`	`0`	Taker fee rate. Negative values rebate.
`tick_scheme_name`	N/A	`str \| None`	`None`	Registered variable tick scheme name.
`info`	`Option<Params>`	`dict \| None`	`None`	Adapter metadata.
`ts_event`	`UnixNanos`	`int`	Required	Event timestamp in nanoseconds.
`ts_init`	`UnixNanos`	`int`	Required	Initialization timestamp in nanoseconds.

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

Behavior

BinaryOption has instrument class BinaryOption.
It is never inverse and uses a multiplier and lot size of one.
Many venues quote binary outcomes between zero and one, but the venue defines the allowed price range and tick size.
outcome and description provide human-readable context for the contract.

Example

use chrono::{TimeZone, Utc};
use nautilus_core::UnixNanos;
use nautilus_model::{
    enums::AssetClass,
    identifiers::{InstrumentId, Symbol, Venue},
    instruments::BinaryOption,
    types::{Currency, Price, Quantity},
};
use rust_decimal_macros::dec;
use ustr::Ustr;

let raw_symbol = Symbol::from(
    "0x12a0cb60174abc437bf1178367c72d11f069e1a3add20b148fb0ab4279b772b2-92544998123698303655208967887569360731013655782348975589292031774495159624905",
);
let expiration = Utc.with_ymd_and_hms(2024, 1, 1, 0, 0, 0).unwrap();

let yes_outcome = BinaryOption::builder()
    .instrument_id(InstrumentId::new(raw_symbol, Venue::from("POLYMARKET")))
    .raw_symbol(raw_symbol)
    .asset_class(AssetClass::Alternative)
    .currency(Currency::from("USDC"))
    .activation_ns(UnixNanos::default())
    .expiration_ns(UnixNanos::from(expiration.timestamp_nanos_opt().unwrap() as u64))
    .price_precision(3)
    .size_precision(2)
    .price_increment(Price::from("0.001"))
    .size_increment(Quantity::from("0.01"))
    .outcome(Ustr::from("Yes"))
    .description(Ustr::from("Will the outcome of this market be 'Yes'?"))
    .min_quantity(Quantity::from("5"))
    .maker_fee(dec!(0))
    .taker_fee(dec!(0))
    .ts_event(UnixNanos::default())
    .ts_init(UnixNanos::default())
    .build()
    .unwrap();

Adapters

Representative adapters that create or consume BinaryOption instruments include:

Hyperliquid for binary and prediction-style markets.
OKX for venue-defined binary outcome products.
Polymarket for prediction market outcomes.

Order Book covers binary market order book behavior.
Data explains market data that references instruments.

Binary Option

Fields

Behavior

Example

Adapters

Related guides

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