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

# Markets and terms

> Read an option market correctly, including its token pair, fixed rate, premium, minimum amount and expiry.

A Ledig option market has a specific token pair, fixed exchange rate and exact expiry. The protocol calls this a **series**. Different rates or expiries create different series, even when the token pair is the same.

Choosing the right series matters because its terms determine what you pay, what you can receive and how long the right lasts. They do not change simply because the wider market moves.

## Read the two token roles

| Token role | What it is used for |
| - | - |
| Collateral and receipt token | Writers deposit this token. Buyers pay their purchase premium in it and receive it when exercising. Technical records call it BASE. |
| Exercise payment token | Buyers provide this token when exercising. Writers earn the corresponding proceeds. Technical records call it STRIKE. |

In an illustrative USDC/cNGN series, USDC is the collateral, premium and receipt token. cNGN is the exercise payment token.

The word **Base**, referring to the blockchain network, is different from the **BASE** token role. A token’s network and contract address also matter: a matching name or symbol alone does not make it the correct asset.

## Strike rate and premium serve different purposes

The **strike rate** is the agreed exchange rate used when exercising. At 1,500 cNGN per USDC, exercising 10,000 USDC of rights requires 15 million cNGN, subject to the tokens’ supported precision.

The **premium** is the price of buying those rights. Writers offer amounts at particular premium percentages. Several offers can share one series’ fixed strike and expiry while charging different premiums.

A 1.8% premium on 100,000 USDC means a gross premium of 1,800 USDC. That percentage is the price for the specified right. It is not an annual interest rate or a promised investment return. See [Pricing and fees](/pricing-and-fees).

## Expiry is an exact deadline

The expiry belongs to the series. Buying into a series does not restart its clock. If a series began with 30 days to expiry and you purchase ten days later, your right has approximately 20 days remaining.

Check the precise date, time and timezone. New purchases and exercise stop at expiry. A transaction must execute before the deadline; submitting it beforehand does not guarantee that it will execute in time.

## Amount, availability and capacity

The amount of an option is expressed in the token the buyer may receive. A 100,000 USDC position therefore means a right to receive up to 100,000 USDC by making the corresponding exercise payment.

Each series has a minimum purchase amount, which also sets the minimum size of a new writer offer. A buyer must meet that minimum for each purchase. Exercising only part of an existing position is a different action and is supported.

Available offers show what writers currently offer for sale. A series also has a limit on cumulative purchases over its life. Exercising or expiring an already purchased option does not refill that purchase capacity. Availability can change before your transaction completes.

## What you should compare before buying

| Check | Why it matters |
| - | - |
| Exact tokens and network | Your wallet must hold the correct assets in the correct environment. |
| Strike rate | Determines the exercise payment. |
| Exact expiry | Determines how long the choice remains available. |
| Total premium | Includes the offers needed to fill your selected amount. |
| Minimum amount and available liquidity | Determine whether the purchase can complete. |

Buying protection and exercising it are separate transactions. Continue to [Buying protection](/buying-protection), or use the [Glossary](/glossary) to look up a term.