Definition

Market Order

An order that demands immediate execution at the best available price. In this framework, market orders are aggression.

Full Explanation

A market order is impatient. It does not specify the exact price it must receive; it demands execution now and accepts the best available liquidity. A market buy trades against sell limit orders at the ask. A market sell trades against buy limit orders at the bid.

That makes market orders aggression. They consume the liquidity that other participants have placed on the book. If the available orders at the best price are large enough, the market order is absorbed there. If they are not, the unfilled portion continues into the next available prices until the order is completed. That movement through available liquidity is relocation.

This is also why a market order can experience slippage. Immediate execution is the priority, not a guaranteed fill price. The more aggression arriving relative to available liquidity, the farther execution may have to travel to find enough resting orders.

In the Book 1 chapter

Chapter 2 · The Mechanics

Liquidity and Aggression

Every single trade has a buyer and a seller. That’s not an insight — it’s just math. For any transaction to happen, someone has to buy and someone has to sell. Which means that when you hear “buyers are in control right now” or “sellers are pushing price down,” you should pause for a second, because those phrases are telling you less than they sound like they are.

From the Blog 1 post

Why "Buyers vs. Sellers" Is the Wrong Frame

Every transaction has both a buyer and a seller. That's not insight — it's arithmetic. The question that actually matters is different, and until you're asking it, you're working with the wrong map.