Terms Used on This Site, Defined Once

Adverse selection

The tendency for the trades you actually get filled on to be the ones your counterparty most wanted to make. In a new pool the counterparty has usually known about the token far longer than your program has, so an easy fill is weak evidence about the candidate rather than proof of speed.

Arrival gap

The interval between an event occurring on the network and your program acting on it. It contains propagation, transport, deserialisation, queueing inside your own process and rule evaluation. Most of it is yours to fix, and the part that is not is usually the smallest.

Associated token account

The token account for a given wallet and mint derived at a deterministic address. Because balances live in token accounts rather than in wallets, a holder read is an enumeration of these accounts rather than a lookup against the mint.

Bonding curve

A launch mechanism where price is a function of supply sold rather than of a two-sided reserve. Curve launches produce their own creation event, which is often the earliest trigger available and carries little market state.

Constant product pool

A pool whose two reserves multiply to a constant, so the price moves as either side is drained. It is the model behind the impact arithmetic used throughout this site: an input equal to a fraction of the reserve moves price by roughly twice that fraction.

Deployer

The account that created the mint. Its history is public, and an address whose first activity was this launch is a materially different proposition from one with unrelated activity going back months.

Effective float

Total supply minus the amount held in the pool, minus anything provably unable to move. It is the supply that can actually arrive as sell pressure, and it is the number worth comparing against pool depth rather than total supply.

Fail closed

The convention that any rule which could not be evaluated rejects the candidate. Timeouts, malformed responses and missing accounts all count. The alternative silently loosens the entire rule set at the moment information is worst.

False positive

A legitimate candidate that a rule rejects. Every threshold produces them by construction, and writing the specific case beside the rule is what turns a guessed number into an examined design decision.

Freeze authority

The mint account field naming an account permitted to freeze individual token accounts. A frozen token account cannot transfer, which makes a live freeze authority the most direct mechanism behind a token that can be bought but not sold.

Honeypot

A token that can be entered and not exited. On Solana this is not one mechanism but several: a live freeze authority, a transfer hook that can reject transfers, or liquidity that can be withdrawn. A useful check is therefore a set of capability checks rather than a single verdict.

Impact tolerance

The price movement you are willing to cause on entry, chosen in advance. It is the input from which a liquidity floor is derived, which is why two operators trading different sizes should have different floors.

Liquidity lock

A claim that the pool position tokens cannot be redeemed for some period. It is verified when those tokens sit in a program account whose terms your code can read, false when they sit in an ordinary wallet, and unverified otherwise. Unverified is treated as absent.

Mint account

The account describing a token: total supply, decimals, and the authority fields governing minting and freezing. It is the cheapest single read in a screening pipeline and rejects a large share of candidates on its own.

Mint authority

The field naming an account permitted to create additional supply. When it is empty, supply is fixed for the token program in use, which is what makes concentration arithmetic meaningful rather than provisional.

Pool token

The token representing a share of a liquidity pool. Whoever holds it can withdraw the corresponding reserves, so identifying its holder is the check behind any statement about whether the market can be removed.

Price impact

The movement in the pool price caused by your own trade. It is paid on entry and again on exit, and the exit is paid against whatever reserve remains at that moment rather than the one that existed at entry.

Quote asset

The asset on the other side of the pool, in which proceeds are received. Composition is checked before magnitude: a large reserve in an asset nobody wants converts one exit problem into two.

Rejection log

The record of every candidate a rule set turned down, with the rule that fired and the value it read. It is the only place a filter set can be improved from, because the admissions are dominated by factors outside the rules.

Rent exemption

The minimum balance an account must hold to persist on Solana without being reclaimed. It is why holding a new token has a fixed cost per mint, and why many very small positions are expensive in aggregate.

Sniper bot

A program that detects a newly created token or pool, applies screening rules, sizes a position and sends an entry transaction. Most of the interesting design work is in the rules; the transaction is comparatively well documented engineering.

Token extension

An optional feature on the newer token program that changes transfer behaviour: a fee on transfers, a hook program that must approve them, or confidential balances. A pipeline written for standard semantics will compute wrong amounts for tokens using them.

Transfer hook

An extension requiring a separate program to approve each transfer. It is a discretionary gate held by somebody else, which makes it a materially different exposure from an arithmetic adjustment such as a transfer fee.

Trigger event

The specific subscription that tells a program a candidate exists. It sets the ceiling on screening quality, because no rule can evaluate state that had not been written when the event fired.

Definitions on this page are descriptive rather than authoritative. Where a term has a precise meaning in the Solana protocol or in a token program, the protocol documentation is the authority and this page is a working summary of how the term is used in the rules described elsewhere on the site.