Equity

Equity represents a listed share, ETF, or similar cash-market security. Nautilus uses this type for instruments that trade in whole units, quote in one currency, and have no contract expiry.

Examples include AAPL.XNAS, MSFT.XNAS, and venue-specific ETF symbols.

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.
`currency`	`Currency`	`Currency`	Required	Quote and settlement currency.
`price_precision`	`u8`	`int`	Required	Decimal places allowed for prices.
`price_increment`	`Price`	`Price`	Required	Smallest valid price step.
`lot_size`	`Option<Quantity>`	`Quantity`	Required/Python	Board lot or whole‑share lot size.
`ts_event`	`UnixNanos`	`int`	Required	Event timestamp in nanoseconds.
`ts_init`	`UnixNanos`	`int`	Required	Initialization timestamp in nanoseconds.
`isin`	`Option<Ustr>`	`str \| None`	`None`	International Securities ID when known.
`max_quantity`	`Option<Quantity>`	`Quantity \| None`	`None`	Maximum order quantity.
`min_quantity`	`Option<Quantity>`	`Quantity \| None`	`None`	Minimum order quantity.
`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>`	`Decimal \| None`	`0`	Initial margin rate.
`margin_maint`	`Option<Decimal>`	`Decimal \| None`	`0`	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.

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

Behavior

Equity has asset class Equity and instrument class Spot.
Quantity precision is always zero, so orders use whole-share quantities.
The multiplier and size increment are one.
It has no base currency, expiry, strike, option kind, or inverse costing flag.
Use price limits only when the venue publishes them.

Example

rust

use nautilus_core::UnixNanos;
use nautilus_model::{
    identifiers::{InstrumentId, Symbol},
    instruments::Equity,
    types::{Currency, Price, Quantity},
};
use ustr::Ustr;

let aapl = Equity::builder()
    .instrument_id(InstrumentId::from("AAPL.XNAS"))
    .raw_symbol(Symbol::from("AAPL"))
    .isin(Ustr::from("US0378331005"))
    .currency(Currency::from("USD"))
    .price_precision(2)
    .price_increment(Price::from("0.01"))
    .lot_size(Quantity::from("100"))
    .ts_event(UnixNanos::default())
    .ts_init(UnixNanos::default())
    .build()
    .unwrap();

python

from nautilus_trader.model.currencies import USD
from nautilus_trader.model.identifiers import InstrumentId
from nautilus_trader.model.identifiers import Symbol
from nautilus_trader.model.instruments import Equity
from nautilus_trader.model.objects import Price
from nautilus_trader.model.objects import Quantity

aapl = Equity(
    instrument_id=InstrumentId.from_str("AAPL.XNAS"),
    raw_symbol=Symbol("AAPL"),
    isin="US0378331005",
    currency=USD,
    price_precision=2,
    price_increment=Price.from_str("0.01"),
    lot_size=Quantity.from_int(100),
    ts_event=0,
    ts_init=0,
)

Adapters

Representative adapters that create or consume Equity instruments include:

Databento for listed US equities and ETFs.
Interactive Brokers for listed equity contracts.

Data explains market data that references instruments.
Value types explains Price, Quantity, and Money.

Equity

Equity

Fields

Behavior

Example

Adapters

Related guides