> ## Documentation Index
> Fetch the complete documentation index at: https://docs.kairos.trade/llms.txt
> Use this file to discover all available pages before exploring further.

# Order Types

> Market orders, limit orders, resting orders, and maker vs taker

Now that you can read a book, you need to tell the exchange what to do with it. This chapter covers the two orders you'll use for almost everything — market and limit — and the maker/taker distinction that decides what you pay in fees.

## Two Ways to Trade

When you want to buy or sell shares, you have two basic choices:

1. **Market order** — "I want to trade right now, at whatever price is available"
2. **Limit order** — "I want to trade at this specific price or better"

## Market Orders

A market order says: **"Just get it done."**

You don't pick a resting price — the exchange matches you with the best available offers on the order book immediately.

<Note>
  **On Kairos:** a market order still requires a `price`. Kairos treats it as the
  limit you authorise it to cross to, not as a "any price" sentinel, and rejects
  the order without one. Send the live same-outcome quote — ask for buys, bid for
  sells. See [Order Types](/guides/order-types) for the API details.
</Note>

**When to use it:**

* You want to trade *right now*
* You care more about speed than getting the perfect price
* The order book has enough depth at reasonable prices

**The catch:** If there isn't much depth, you might get a worse price than expected. This is called **slippage** (covered in a later chapter).

**Example:** You market buy 100 shares. The book has 80 at $0.55 and 150 at $0.57:

| Price | Shares | Cost |
| - | - | - |
| \$0.55 | 80 | \$44.00 |
| \$0.57 | 20 | \$11.40 |
| **Avg \$0.554** | **100** | **\$55.40** |

## Limit Orders

A limit order says: **"I'll only trade at this price or better."**

You set your price. If the market can fill you at that price (or a better one), it does. If not, your order waits.

**When to use it:**

* You have a specific price in mind
* You're not in a rush
* You want to control your cost

> **You:** Limit buy 100 at **\$0.53**
>
> **Book:** Best ask is **$0.55** — no one selling at **$0.53**
>
> **Result:** Order rests on the book and waits.
>
> *...later, someone sells at **\$0.53**...*
>
> **Result:** Filled!

## Resting Orders

When a limit order can't fill immediately, it **rests** on the order book. It becomes a bid (if buying) or an ask (if selling) that other traders can trade against.

Your resting order stays on the book until:

* Someone takes the other side (you get filled)
* You cancel it
* It expires (depending on time-in-force settings)

Think of it like leaving a note at the auction: *"If anyone wants to sell at **\$0.53**, I'm buying."*

## Maker vs Taker

These terms describe your role in a trade:

| Role | What You Did | Example |
| - | - | - |
| **Maker** | Added liquidity — your order rested on the book and someone else traded against it | Limit buy at **\$0.53**, it rested, later got filled |
| **Taker** | Removed liquidity — you traded against someone else's resting order | Market buy that ate into the existing asks |

**Why it matters:** Many exchanges charge lower fees for makers (sometimes zero). Makers help the market by providing liquidity. Takers pay a bit more for the convenience of instant execution.

<Note>
  **On Kairos:** the exact maker and taker rates depend on the venue and on your
  fee tier, and one venue inverts the usual direction. See
  [Fees](/trading/fees) before assuming maker is the cheap side.
</Note>

## Quick Comparison

| | **Market Order** | **Limit Order** |
| - | - | - |
| **Speed** | Instant | May wait |
| **Price control** | None | Full — you set the price |
| **Guaranteed fill?** | No — only if the book has depth inside your price | No |
| **Role** | Taker | Maker (if it rests) or Taker |
| **Best for** | "I need this now" | "I want a good price" |

## A Simple Rule of Thumb

* **In a hurry?** Market order.
* **Have a target price?** Limit order.
* **Want lower fees?** Limit order (maker).

**Next:** [Time-in-Force](/learn/time-in-force) — how long an order should stay alive, and what to do if it can't fill completely.


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