---
title: "Alpaca"
description: "This page explains the default security-level models and markets of the AlpacaBrokerageModel."
canonical: https://www.quantconnect.com/docs/v2/writing-algorithms/reality-modeling/brokerages/supported-models/alpaca
markdown: https://www.quantconnect.com/docs/v2/writing-algorithms/reality-modeling/brokerages/supported-models/alpaca.md
language: python
source: https://github.com/QuantConnect/Documentation/tree/master/03%20Writing%20Algorithms/24%20Reality%20Modeling/05%20Brokerages/02%20Supported%20Models/06%20Alpaca
modified: 2026-10-30
index: https://www.quantconnect.com/llms.txt
---

# Alpaca

[Documentation](https://www.quantconnect.com/docs/v2.md) > [Writing Algorithms](https://www.quantconnect.com/docs/v2/writing-algorithms.md) > Reality Modeling > Brokerages > [Supported Models](https://www.quantconnect.com/docs/v2/writing-algorithms/reality-modeling/brokerages/supported-models.md) > Alpaca

> Code examples are shown in Python. Append `?lang=csharp` to this URL for the C# version of this page.

## Introduction

This page explains the `AlpacaBrokerageModel`, including the asset classes it supports, its default [security-level models](https://www.quantconnect.com/docs/v2/writing-algorithms/reality-modeling/key-concepts.md#02-Security-Level-Models), and its default markets.

```python
self.set_brokerage_model(BrokerageName.ALPACA, AccountType.CASH)
self.set_brokerage_model(BrokerageName.ALPACA, AccountType.MARGIN)
```

For more information about this model, see the [class reference](https://www.lean.io/docs/v2/lean-engine/class-reference/py/QuantConnect/Brokerages/AlpacaBrokerageModel/) and [implementation](https://github.com/QuantConnect/Lean/blob/master/Common/Brokerages/AlpacaBrokerageModel.cs).

## Asset Classes

The `AlpacaBrokerageModel` supports the following asset classes:

- [US Equities](https://www.quantconnect.com/docs/v2/writing-algorithms/securities/asset-classes/us-equity.md)
- [Equity Options](https://www.quantconnect.com/docs/v2/writing-algorithms/securities/asset-classes/equity-options.md)
- [Index Options](https://www.quantconnect.com/docs/v2/writing-algorithms/securities/asset-classes/index-options.md)
- [Crypto](https://www.quantconnect.com/docs/v2/writing-algorithms/securities/asset-classes/crypto.md)

## Orders

The `AlpacaBrokerageModel` supports several order types, order properties, and most order updates.

### Order Types

The following table describes the available order types for each asset class that the `AlpacaBrokerageModel` supports:

| Order Type | Equity | Equity Options | Index Options | Crypto |
| --- | --- | --- | --- | --- |
| [Market](https://www.quantconnect.com/docs/v2/writing-algorithms/trading-and-orders/order-types/market-orders.md) | ![green check](https://cdn.quantconnect.com/i/tu/check.png) | ![green check](https://cdn.quantconnect.com/i/tu/check.png) | ![green check](https://cdn.quantconnect.com/i/tu/check.png) | ![green check](https://cdn.quantconnect.com/i/tu/check.png) |
| [Limit](https://www.quantconnect.com/docs/v2/writing-algorithms/trading-and-orders/order-types/limit-orders.md) | ![green check](https://cdn.quantconnect.com/i/tu/check.png) | ![green check](https://cdn.quantconnect.com/i/tu/check.png) | ![green check](https://cdn.quantconnect.com/i/tu/check.png) | ![green check](https://cdn.quantconnect.com/i/tu/check.png) |
| [Stop market](https://www.quantconnect.com/docs/v2/writing-algorithms/trading-and-orders/order-types/stop-market-orders.md) | ![green check](https://cdn.quantconnect.com/i/tu/check.png) |  |  |  |
| [Stop limit](https://www.quantconnect.com/docs/v2/writing-algorithms/trading-and-orders/order-types/stop-limit-orders.md) | ![green check](https://cdn.quantconnect.com/i/tu/check.png) |  |  | ![green check](https://cdn.quantconnect.com/i/tu/check.png) |
| [Trailing stop](https://www.quantconnect.com/docs/v2/writing-algorithms/trading-and-orders/order-types/trailing-stop-orders.md) | ![green check](https://cdn.quantconnect.com/i/tu/check.png) |  |  |  |
| [Market on Open](https://www.quantconnect.com/docs/v2/writing-algorithms/trading-and-orders/order-types/market-on-open-orders.md) | ![green check](https://cdn.quantconnect.com/i/tu/check.png) |  |  |  |
| [Market on Close](https://www.quantconnect.com/docs/v2/writing-algorithms/trading-and-orders/order-types/market-on-close-orders.md) | ![green check](https://cdn.quantconnect.com/i/tu/check.png) |  |  |  |
| [Combo market](https://www.quantconnect.com/docs/v2/writing-algorithms/trading-and-orders/order-types/combo-market-orders.md) |  | ![green check](https://cdn.quantconnect.com/i/tu/check.png) | ![green check](https://cdn.quantconnect.com/i/tu/check.png) |  |
| [Combo limit](https://www.quantconnect.com/docs/v2/writing-algorithms/trading-and-orders/order-types/combo-limit-orders.md) |  | ![green check](https://cdn.quantconnect.com/i/tu/check.png) | ![green check](https://cdn.quantconnect.com/i/tu/check.png) |  |
| [Bracket](https://www.quantconnect.com/docs/v2/writing-algorithms/trading-and-orders/order-types/contingent-orders/bracket-orders.md) | ![green check](https://cdn.quantconnect.com/i/tu/check.png) |  |  |  |
| [One cancels other](https://www.quantconnect.com/docs/v2/writing-algorithms/trading-and-orders/order-types/contingent-orders/one-cancels-other-orders.md) | ![green check](https://cdn.quantconnect.com/i/tu/check.png) |  |  |  |
| [One triggers other](https://www.quantconnect.com/docs/v2/writing-algorithms/trading-and-orders/order-types/contingent-orders/one-triggers-other-orders.md) | ![green check](https://cdn.quantconnect.com/i/tu/check.png) |  |  |  |

Combo orders must have 2 to 4 Option legs.

### Order Properties

The `AlpacaBrokerageModel` supports custom order properties. The following table describes the members of the `AlpacaOrderProperties` object that you can set to customize order execution.

| Property | Data Type | Description | Default Value |
| --- | --- | --- | --- |
| `time_in_force` | `TimeInForce` | A [TimeInForce](https://www.quantconnect.com/docs/v2/writing-algorithms/trading-and-orders/order-properties.md#03-Time-In-Force) instruction to apply to the order. The following instructions are supported: `DAY` `GOOD_TIL_CANCELED` Option orders always use `DAY`. | `TimeInForce.GOOD_TIL_CANCELED` |
| `outside_regular_trading_hours` | `bool` | A flag to signal that the order may be triggered and filled outside of regular trading hours. Only limit orders with the `DAY` time in force support it. | `False` |

```python
def initialize(self) -> None:
    # Set the default order properties
    self.default_order_properties = AlpacaOrderProperties()
    self.default_order_properties.outside_regular_trading_hours = False
    self.default_order_properties.time_in_force = TimeInForce.GOOD_TIL_CANCELED

def on_data(self, slice: Slice) -> None:
    # Use default order order properties
    self.limit_order(self._symbol, quantity, limit_price)

    # Override the default order properties
    order_properties = AlpacaOrderProperties()
    order_properties.time_in_force = TimeInForce.DAY
    self.limit_order(self._symbol, quantity, limit_price, order_properties=order_properties)

    order_properties.outside_regular_trading_hours = True
    self.limit_order(self._symbol, quantity, limit_price, order_properties=order_properties)
```

### Contingent Orders

Alpaca accepts [contingent orders](https://www.quantconnect.com/docs/v2/writing-algorithms/trading-and-orders/order-types/contingent-orders.md) for Equities with the following rules:

- A set has up to three orders for the same security: a bracket order, an entry order that triggers one exit order, or a one cancels other pair of exit orders.
- An exit order is a limit order (take profit) or a stop market or stop limit order (stop loss).
- A one cancels other pair has one take-profit order and one stop-loss order on the same side, and it exits an existing position.
- You can update the prices of the orders in a set, but not their quantities.

### Updates

The `AlpacaBrokerageModel` supports [order updates](https://www.quantconnect.com/docs/v2/writing-algorithms/trading-and-orders/order-management/order-tickets.md#04-Update-Orders).

### Handling Splits

If you're using raw [data normalization](https://www.quantconnect.com/docs/v2/writing-algorithms/securities/asset-classes/us-equity/requesting-data.md#11-Data-Normalization) and you have active orders with a limit, stop, or trigger price in the market for a US Equity when a [stock split](https://www.quantconnect.com/docs/v2/writing-algorithms/securities/asset-classes/us-equity/corporate-actions.md#02-Splits) occurs, the following properties of your orders automatically adjust to reflect the stock split:

- Quantity
- Limit price
- Stop price
- Trigger price

## Fills

The `AlpacaBrokerageModel` uses the [EquityFillModel](https://www.quantconnect.com/docs/v2/writing-algorithms/reality-modeling/trade-fills/supported-models/equity-model.md) for Equity trades and the [ImmediateFillModel](https://www.quantconnect.com/docs/v2/writing-algorithms/reality-modeling/trade-fills/supported-models/immediate-model.md) for Option and Crypto trades.

## Slippage

The `AlpacaBrokerageModel` uses the [NullSlippageModel](https://www.quantconnect.com/docs/v2/writing-algorithms/reality-modeling/slippage/supported-models.md#02-Null-Model).

## Fees

The `AlpacaBrokerageModel` uses the [AlpacaFeeModel](https://www.quantconnect.com/docs/v2/writing-algorithms/reality-modeling/transaction-fees/supported-models.md#03-Alpaca-Model) with the default argument values. We model current Alpaca fees on all assets.

## Buying Power

The `AlpacaBrokerageModel` uses the `CashBuyingPowerModel` for cash accounts, the `SecurityMarginModel` for margin accounts, and the `OptionMarginModel` for Option trades.

If you have a margin account, the `AlpacaBrokerageModel` allows 2x leverage for Equities and 3x leverage for Crypto.

## Settlement

The `AlpacaBrokerageModel` uses the [ImmediateSettlementModel](https://www.quantconnect.com/docs/v2/writing-algorithms/reality-modeling/settlement/supported-models.md#02-Immediate-Model) for margin accounts and the [DelayedSettlementModel](https://www.quantconnect.com/docs/v2/writing-algorithms/reality-modeling/settlement/supported-models.md#03-Delayed-Model) with the [default settlement rules](https://www.quantconnect.com/docs/v2/writing-algorithms/reality-modeling/settlement/key-concepts.md#03-Default-Behavior) for cash accounts with Equity and Equity Options.

```python
# For US Equities with a cash account:
security.set_settlement_model(DelayedSettlementModel(Equity.DEFAULT_SETTLEMENT_DAYS, Equity.DEFAULT_SETTLEMENT_TIME))

# For Equity Options with a cash account:
security.set_settlement_model(DelayedSettlementModel(Option.DEFAULT_SETTLEMENT_DAYS, Option.DEFAULT_SETTLEMENT_TIME))

# For remaining cases:
security.set_settlement_model(ImmediateSettlementModel())
```

## Margin Interest Rate

The `AlpacaBrokerageModel` uses the [NullMarginInterestRateModel](https://www.quantconnect.com/docs/v2/writing-algorithms/reality-modeling/margin-interest-rate/supported-models.md#02-Null-Model).

## Default Markets

The default market of the `AlpacaBrokerageModel` is `Market.USA` for Equity, Equity Options, and Index Options. It's `Market.COINBASE` for Crypto.

## Account Currency

The `AlpacaBrokerageModel` doesn't set a default currency. To change the algorithm's currency from USD to a different currency, see [Set Account Currency](https://www.quantconnect.com/docs/v2/writing-algorithms/initialization.md#03-Set-Account-Currency).