Pegged Order Types: Prices That Track the Market

Key Takeaways

• Pegged order types reprice automatically as the NBBO moves, tracking a chosen reference.
• The three core variants peg to the near side, the far side, or the midpoint.
• An optional offset shifts the price to make the order more passive or aggressive.
• Pegging keeps an order competitive without manual repricing, but cedes price control.

What Pegged Order Types Are

Pegged order types are orders whose price is defined relative to a moving market reference rather than as a fixed number. As the National Best Bid and Offer (NBBO) shifts, the exchange recalculates the order's price to stay anchored to its reference. Nasdaq's rulebook describes pegging "with reference to" a quotation, such as the inside bid, the inside offer, or the midpoint between them.

The three core variants differ only in their anchor. A primary peg tracks the near side of the market, a market peg tracks the far side, and a midpoint peg tracks the point halfway between bid and offer. Each can also carry an offset that nudges the price by a set increment.

The Intuition

A static limit order goes stale the moment the market moves. If you post a bid and the whole market ticks up, your order is suddenly behind the queue and unlikely to fill. Manually canceling and replacing it dozens of times is slow and error prone.

Pegging automates that chase. You decide what the order should track, and the exchange keeps it pinned there as quotes change. You give up naming an exact price in exchange for staying continuously relevant to wherever the market currently sits.

How It Works

Each pegged order names a reference price, and the matching engine reprices the order whenever that reference changes. An optional offset shifts the price away from the reference in either direction.

Primary peg: tracks the near side (bid for buys, offer for sells)
Market peg:  tracks the far side (offer for buys, bid for sells)
Midpoint peg: tracks the midpoint between bid and offer
Offset:      passive (less aggressive) or aggressive (closer to filling)

Aggressiveness rises as the anchor moves toward the far side. A primary peg is the most passive, resting on your own side of the market. A market peg is the most aggressive, sitting where it can execute against resting liquidity right away. A midpoint peg lands between them and is non-displayed, so it can capture price improvement at the midpoint. Nasdaq notes that an offset can make a pegged order "more passive or aggressive" by a chosen increment, so the same peg type can be tuned in either direction.

Worked Example

The NBBO for a stock is 11.00 bid, 11.06 offer, so the midpoint is 11.03. A trader wants to buy and considers three pegged choices.

A primary peg to buy anchors to the bid and rests at 11.00, the most passive option. A midpoint peg rests at 11.03, non-displayed, ready to trade against contra interest at the midpoint. A market peg to buy anchors to the offer at 11.06, the most aggressive, immediately executable against the resting offer. If the bid then rises to 11.01 and the offer to 11.07, all three reprice automatically: the primary peg moves to 11.01, the midpoint to 11.04, and the market peg to 11.07. The trader never touched the order, yet each stayed anchored to its reference.

Common Mistakes

1. Picking the wrong reference. A primary peg and a market peg behave very differently in fill probability. Choosing the far side when you wanted to rest passively can fill you instantly at a worse price.
2. Ignoring the offset direction. A passive offset pulls you away from filling; an aggressive offset pushes you toward it. Confusing the two changes execution entirely.
3. Assuming pegs are always displayed. Midpoint pegs are non-displayed, and some primary pegs are hidden, so others may not see them.
4. Forgetting venue rules differ. Each exchange defines pegging slightly differently, including which variants are offered and how offsets are capped.
5. Overlooking the limit cap. A pegged order can carry a limit that stops it repricing past a point, and forgetting it can leave the order stuck when the market moves.

Frequently Asked Questions

What are pegged order types in simple terms? Pegged order types automatically change their price as the market moves, tracking a reference such as the bid, the offer, or the midpoint. You set what they follow, and the exchange keeps them pinned there.

How do pegged order types affect investment decisions? They let you stay competitive without manually repricing, trading exact price control for continuous relevance. In the worked example, three pegs anchored to the bid, midpoint, and offer all repriced themselves when the NBBO ticked up.

What is a real-world example of pegged order types? With a market of 11.00 bid and 11.06 offer, a primary peg rests at 11.00, a midpoint peg at 11.03, and a market peg at 11.06, and each moves automatically as quotes change.

How can investors use pegged order types effectively? Match the reference to your goal: primary for passive resting, market for aggressive execution, midpoint for price improvement, and use offsets and a limit cap to control behavior.

How are pegged order types different from a standard limit order? A limit order holds one fixed price and goes stale when the market moves. A pegged order reprices itself to track a reference, staying anchored to the market without manual updates.

Sources

1. Nasdaq Rule Filing SR-NASDAQ-2016-039, Order Type Definitions. U.S. Securities and Exchange Commission. https://www.sec.gov/files/rules/sro/nasdaq/2016/34-77454-ex5.pdf
2. Nasdaq. North American Markets Order Types and Modifiers. https://www.nasdaqtrader.com/content/productsservices/trading/ordertypesg.pdf
3. IEX Exchange. Order Type Summaries. https://www.iexexchange.io/products/order-types
4. SEC Investor.gov. Investor Bulletin: Understanding Order Types. https://www.investor.gov/introduction-investing/general-resources/news-alerts/alerts-bulletins/investor-bulletins-14

Disclaimer

This article is educational content only and is not financial advice. Nothing here is a recommendation to buy, sell, or hold any security. Consult a licensed advisor before making investment decisions.