Law of one price

This one is not written up yet

The definition above is the short version. A full explanation — how it works, a worked example and the exam traps — is still being written. In the meantime the chapter below covers it in context.

Written up from the same chapter

• BasisThe difference between the spot price and the futures price of an asset — positive when spot exceeds futures, negative when futures exceeds spot, and zero at expiry.
• DerivativeA contract whose value is derived from the value of something else — the underlying — rather than from anything the contract itself owns or produces.
• Exchange traded derivativeA derivative traded on an organised exchange on standardised terms, with prices set by anonymous auction and performance guaranteed by a clearing corporation — as against a bilateral, customised OTC contract.
• Forward contractA bilateral, over-the-counter agreement between two parties to buy or sell an asset on a fixed future date at a price agreed today — customised to suit them, and binding on both.
• Futures contractA standardised forward traded on an exchange, where the exchange fixes every term except the price and the clearing corporation guarantees settlement, so neither side carries the other's default risk.
• HedgingTaking a derivative position that moves opposite to an exposure you already have, so gains on one offset losses on the other and the future rate is locked in at a known level.