Pegged Orders Explained (Pegged-to-Best / Midpoint / Primary / Market / Limit)

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Written By
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Written By
Dan Buckley
Dan Buckley is an US-based trader, consultant, and part-time writer with a background in macroeconomics and mathematical finance. He trades and writes about a variety of asset classes, including equities, fixed income, commodities, currencies, and interest rates. As a writer, his goal is to explain trading and finance concepts in levels of detail that could appeal to a range of audiences, from novice traders to those with more experienced backgrounds.

Pegged orders are a type of order used in trading that automatically adjusts its price based on certain market conditions.

These orders are designed to provide traders with more strategic control over their trades, so they remain competitive in changing markets.

There are various types of pegged orders, each with its unique features and applications.


Key Takeaways – Pegged Orders

  • Peg algos automatically adjust order prices to remain competitive based on market benchmarks.
  • They help orders stay relevant with dynamic pricing.
  • Offer strategic advantages in fast-moving markets.
  • Different types of pegged orders (e.g., Pegged-to-Best, Midpoint, Market Pegged) cater to various trading strategies, and balance competitiveness with regulatory compliance.


Pegged-to-Best Orders

Pegged-to-Best orders are designed to ensure that an order remains competitive by automatically adjusting its price to be slightly better than the current best price available in the market or the best price offered by other similar orders within the trading system.

This type of order aims to increase the likelihood of execution by staying close to the forefront of market movements, up to a defined limit price.


Midpoint Pegged Orders

Midpoint pegged orders are set to automatically adjust their price to match the midpoint of the current best bid and ask prices in the market.

This ensures that the order remains neutral and is executed at a fair price relative to the current market conditions.

It’s useful in markets where the bid-ask spread is variable, and helps to achieve a balance between buying and selling prices.


Primary Pegged Orders

Primary pegged orders adjust their price in relation to the primary market’s current best bid (for sell orders) or ask (for buy orders) prices.

This type of order seeks to ensure that it remains competitive within the primary market by automatically adjusting to changes in the market’s leading bid or ask prices.


Market Pegged Orders

Market pegged orders are designed to track and automatically adjust to changes in the overall market price.

These orders are pegged to the current market price but can be set with an offset to ensure the order executes at a price slightly better or worse than the market price (depending on the trader’s strategy).

This type of order is useful for traders looking to follow the market’s momentum.


Limit Pegged Orders

Limit pegged orders combine the features of pegged orders with the security of a limit order.

While the order price automatically adjusts based on market conditions, it won’t exceed a predetermined limit price.

This ensures that the order remains competitive but doesn’t execute at a price beyond what the trader is willing to accept.

It essentially balances flexibility and control over the execution price.


How Peg Algos Work

Pegged algorithms, or peg algos, are a type of trading algorithm used in financial markets to automatically adjust the price of an order based on certain reference values.

These algorithms are designed to keep the order price competitive within the market by pegging it to moving benchmarks.

Here’s an explanation of how peg algos work across different order types:

Basic Principle of Peg Algos

At its core, a peg algo keeps your order price automatically updated in response to changes in the market.

This ensures that the order remains relevant to the current market and has a higher chance of execution without the need to manually adjust the price.

Pegged-to-Best Orders

  • Function – Adjusts the order price to be slightly better than the current best market price or the best price on the same side within a trading system.
  • How It Works – If the best bid in the market is $10.00, a Pegged-to-Best buy order might automatically set itself to $10.01 to stay competitive.

Midpoint Pegged Orders

  • Function – Keeps the order price pegged at the midpoint between the best bid and ask prices in the market.
  • How It Works – If the market bid is $10.00 and the ask is $10.10, a Midpoint Pegged order would be priced at $10.05.

Primary Pegged Orders

  • Function – Adjusts the order price in relation to the primary market’s current best bid or ask.
  • How It Works – If you’re selling, and the best ask is $10.10, your order might peg to $10.09 to stay ahead of the competition.

Market Pegged Orders

  • Function – These orders are pegged to the overall market price with an optional offset.
  • How It Works – You can set your order to always be $0.01 less than the market price for a buy order. Adjusts as the market moves.

Limit Pegged Orders

  • Function – Combines pegging features with a limit to ensure the order doesn’t execute beyond a certain price.
  • How It Works – If you set a limit pegged buy order with a limit of $10.50, the order will adjust with the market but never go above $10.50.

Implementation and Compliance

Peg algos use real-time data to adjust order prices automatically.

They comply with regulations like the sub-penny rule by adjusting in permissible increments.

For example, orders over $1.00 must adjust in increments of no less than one cent.

These algorithms are useful for maintaining competitiveness in fast-moving markets and can help traders execute orders closer to their desired price points without constant manual adjustments.


When Should I Use Pegged Orders Instead of Limit Orders or Adaptive Algorithms?

You should consider using pegged orders instead of limit orders or adaptive algorithms in the following scenarios:

When Seeking Price Improvement within a Tight Range

If you aim to achieve a better execution price close to the current market levels but with flexibility, pegged orders can automatically adjust to remain competitive.

They offer potential price improvement without setting a fixed limit.

In Highly Volatile Markets

Pegged orders are ideal in volatile markets where prices fluctuate rapidly.

They adjust in real-time.

This keeps your order relevant and increases the chances of execution without constant manual intervention (i.e., setting new limit orders).

When You Want to Maintain Anonymity and Flexibility

Pegged orders, especially those like Midpoint Pegged, allow you to search for better execution while not necessarily showing your true order intentions to the market.

This maintains flexibility in how your order competes with others and is important for larger traders or institutions who have greater market impact.


Limit orders are better when you have a specific price in mind and are willing to wait for the market to reach that price, regardless of how market conditions might change.

Adaptive algorithms, conversely, are more suited for optimizing execution by dynamically adjusting to market conditions – but they may not always prioritize price improvement or anonymity as pegged orders do.

Pegged orders balance between seeking price improvement and adapting to market changes, which makes them a strategic choice under specific market conditions and trading objectives.



Each of these pegged order types offers unique advantages, and allows traders to implement more nuanced and dynamic trading execution strategies.

By understanding the characteristics and appropriate use cases for each type, traders can optimize their trading approach to better align with their market outlook and risk tolerance and control transaction costs.