Trading Glossary

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ABI (Application Binary Interface)

The specification describing how to encode calls to a contract and decode its responses. Required by any client interacting with the contract.

Access Control

The mechanisms restricting which addresses may invoke privileged functions.

Access Control Flaw

A missing or incorrect permission check allowing unauthorized invocation of privileged functions. Consistently one of the highest-loss vulnerability classes.

Account Abstraction

The design approach that allows accounts to define their own validation logic rather than being bound to a single signature scheme, making features such as gas sponsorship, batching, and social recovery possible at the protocol or standard level.

Account Model

The accounting model used by Ethereum and most smart-contract chains, in which the ledger is a mapping of addresses to balances and contract storage.

Active Addresses

The count of unique addresses transacting in a period, a common proxy for network usage.

Actively Validated Service (AVS)

A service that sources its security from a restaking network rather than bootstrapping its own validator set.

Address

A shortened, encoded representation derived from a public key, used as the destination for transfers.

Address Clustering

Heuristic grouping of addresses believed to be controlled by the same entity.

Address Poisoning

Sending zero-value transactions from an address resembling one the user has previously interacted with, hoping the user later copies the wrong address from their history.

Address Whitelisting

A control restricting withdrawals to a pre-approved set of addresses, typically with a mandatory delay before additions take effect.

Agentic Payments

Payment infrastructure designed for machine-initiated transactions, including granular authorization and spending limits.

AI Agent (On-Chain)

Autonomous software that holds assets and transacts on-chain according to its objectives, an emerging area intersecting with account abstraction and intent architectures.

Air-Gapped

Describing a device with no network connectivity of any kind, where transactions are transferred by QR code, SD card, or similar.

Airdrop

A distribution of tokens to a defined set of addresses, usually without direct payment.

Airdrop Farming

Systematically using protocols specifically to qualify for anticipated distributions.

Algorithmic Stablecoin

A stablecoin relying on supply adjustment mechanisms rather than full collateral backing. The category has a documented history of severe failures and warrants explicit risk language in any customer-facing description.

All-Time High (ATH) / All-Time Low (ATL)

The highest and lowest prices ever recorded for an asset.

Allowlist (Whitelist)

A pre-approved list of addresses permitted to mint early or at a preferential price.

Alpha

Valuable non-public or early information.

Altcoin

Any cryptocurrency other than Bitcoin. Increasingly imprecise; prefer more specific classification in formal material.

Altseason

A market phase in which non-Bitcoin assets outperform.

Analytics Platform

Tooling for querying and visualizing on-chain data.

Annual Percentage Rate (APR)

Annualized return excluding the effect of compounding.

Annual Percentage Yield (APY)

Annualized return including compounding. Advertised DeFi yields are frequently variable and incentive-dependent; presenting them without that context is a compliance risk.

Anon

A pseudonymous participant.

Anonymity Set

The group of possible participants a given transaction could be attributed to. Larger sets provide stronger privacy.

Anti-Money Laundering (AML)

The framework of laws, controls, and procedures for detecting and preventing the laundering of illicit proceeds.

Ape In

To enter a position quickly and with substantial size, typically with minimal research.

Appchain

A blockchain purpose-built for a single application, offering dedicated block space and customizable rules.

Approval (Allowance)

A grant permitting a contract to move a specified amount of tokens from a user's balance. A necessary step in most token interactions and a common attack surface when granted without limit.

Approval Hygiene

The practice of periodically reviewing and revoking outstanding token allowances.

Arbitrage

Profiting from price differences for the same asset across venues or instruments.

Arbitrage MEV

Capturing price differences across venues within a single block.

Archive Node

A full node that additionally retains every historical state, not just the current one. Required for historical queries and analytics; substantially higher storage cost.

Arweave

A storage network offering permanent, one-time-payment data retention.

ASIC (Application-Specific Integrated Circuit)

Hardware built for a single hashing algorithm, dramatically more efficient than general-purpose processors.

Ask (Offer)

The lowest price a seller is asking.

Atomic Swap

A direct exchange between parties on different chains, structured so that either both transfers complete or neither does.

Atomicity

The property that a transaction either fully succeeds or has no effect at all.

Attack Vector

The specific path through which a system can be compromised.

Attestation

A validator's signed vote on the validity and position of a block.

Audit

An independent expert review of contract code for security vulnerabilities and logic errors. An audit reduces risk; it does not eliminate it, and this distinction should be communicated clearly in any customer-facing material.

Auto-Compounding

Automatically reinvesting earned rewards to compound returns.

Auto-Deleveraging (ADL)

A mechanism reducing profitable opposing positions when the insurance fund cannot absorb a bankrupt position.

Automated Market Maker (AMM)

A DEX design that prices assets algorithmically against pooled reserves rather than matching individual buyers and sellers.