Read the two token roles
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.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
Buying protection and exercising it are separate transactions. Continue to Buying protection, or use the Glossary to look up a term.

