Research · Trading Glossary
Trading Glossary
Plain-English definitions of the trading terms that start with O.
O
- OFAC
- The US Office of Foreign Assets Control, which administers US sanctions programs.
- Off-Chain Governance
- Signalling and deliberation conducted outside the chain, with execution performed separately by authorized signers.
- Off-Ramp
- A service converting crypto back into fiat currency.
- OHLC
- Open, high, low, close: the four price points defining a candle.
- Omnibus Account
- A pooled account holding multiple clients' assets under one venue-level account.
- Omnichain
- A design philosophy treating multiple chains as a single unified environment from the user's perspective.
- On-Chain Analysis
- Analysis of blockchain data — flows, holder distribution, exchange balances, active addresses — to infer market conditions.
- On-Chain Governance
- Voting and execution occurring directly on the blockchain, with approved proposals executing automatically.
- On-Chain NFT
- An NFT whose artwork and metadata are stored entirely on the blockchain, removing dependence on external hosting.
- On-Ramp
- A service converting fiat currency into crypto.
- One-Cancels-the-Other (OCO)
- Paired orders where execution of one automatically cancels the other.
- Opcode
- A single low-level instruction in the virtual machine's instruction set, each with an associated gas cost.
- Open Interest
- The total value of outstanding derivative contracts. A measure of capital committed to the market.
- Optimistic Rollup
- A rollup that assumes posted state transitions are valid and provides a window during which anyone may submit a fraud proof challenging them.
- Options
- Contracts granting the right, but not the obligation, to buy (call) or sell (put) at a set price before or at expiry.
- Oracle
- A service delivering external data to smart contracts, which cannot access off-chain information natively.
- Oracle Manipulation
- Distorting a price feed to trigger favourable protocol behaviour, typically mispriced borrowing or unwarranted liquidations.
- Oracle Node
- An entity that sources off-chain data and publishes it on-chain for smart contracts to consume.
- Order Book
- The record of resting buy and sell orders at each price level.
- Order Flow
- The sequence and composition of executed orders, analyzed to infer buying and selling pressure.
- Order Flow Auction (OFA)
- A market in which the right to execute user transactions is auctioned, with proceeds partly returned to users.
- Ordinals
- A convention for individually numbering satoshis, enabling data to be attached to specific units of Bitcoin.
- Orphan Block / Stale Block
- A validly produced block that is not included in the canonical chain because a competing block was adopted instead.
- Out of Gas
- A revert caused by execution exceeding the gas limit.
- Over-the-Counter (OTC) Desk
- A service executing large trades bilaterally, away from public order books, to minimize market impact.
- Overcollateralization
- Requiring collateral worth more than the loan, the standard model in permissionless lending since borrowers are pseudonymous.