LEARN / REFERENCE
Glossary
Short, plain definitions. Each lesson links here the first time it uses a term.
Agent
A system that can plan steps, call tools and use outputs to decide what to do next. NIST ↗
Algorithm
A defined procedure that turns inputs into outputs. It need not use AI. SEC ↗
Backtest
A replay of a strategy on past observations, with modeled decisions and fills. SSRN ↗
Call option
A contract giving its buyer a right to buy the underlying under specified terms. Investor.gov ↗
Candle
A time-bucket summary of market observations, often open, high, low and close. SEC ↗
Colocation
Placing trading servers near a venue’s systems to reduce communication delay. SEC ↗
CTA
Commodity trading advisor; some use systematic managed-futures strategies, others discretionary methods. CME ↗
Custody and self-custody
Who controls access keys for a crypto asset. Self-custody puts that responsibility on the holder. Investor.gov ↗
Deterministic rule
A specified calculation that returns the same result for the same inputs and version. SEC ↗
Expiration
The date or time an option contract ends under its terms. Investor.gov ↗
Funding payment
A periodic payment in some perpetual contracts, often used to help align contract and spot prices. CFTC ↗
Futures contract
A derivative contract with exposure and settlement terms rather than spot ownership. CFTC ↗
Greeks
Model-based measures of option-price sensitivity to inputs such as underlying price, time and volatility. Investor.gov ↗
High-frequency trading
A broad name for automated strategies characterized by fast decisions and order activity. SEC ↗
Buy and hold
A comparison that buys an asset and keeps it instead of repeatedly trading. SEC ↗
Kill switch
An independent control that stops new actions when a safety condition is met. SEC ↗
Leverage
Exposure larger than the capital posted to support it. CFTC ↗
Liquidation
Forced reduction or closure of a margined position under venue rules. CFTC ↗
Live execution
Real orders sent to a venue; distinct from simulated paper fills. SEC ↗
Lookahead bias
Using information in a test that was not available when the simulated decision happened. Freqtrade docs ↗
Margin
Collateral supporting a derivatives position. CFTC ↗
Market maker
A participant that posts buy and sell quotes and manages the resulting inventory risk. SEC ↗
Mean reversion
A hypothesis that a measured deviation from a reference may reverse. SEC ↗
Statistical model
A method fitted to data to estimate a score, forecast or classification. SEC ↗
Oracle
A system that brings external reference data into a blockchain application. Pyth ↗
Order book
The venue’s collection of resting buy and sell orders. SEC ↗
Overfitting
Selecting a method that matches past noise rather than a durable relationship. SSRN ↗
Forward paper test
A simulated strategy run on new observations after the rules are fixed. SEC ↗
Perpetual contract
A derivative with no fixed expiration; its terms commonly include funding payments. CFTC ↗
Liquidity pool
Assets held by a smart contract to support swaps under that pool’s rules. Uniswap ↗
Put option
A contract giving its buyer a right to sell the underlying under specified terms. Investor.gov ↗
Slippage
The difference between a reference or expected price and the actual or modeled fill. SEC ↗
Spot trade
An exchange of the asset itself rather than a futures or options contract. CFTC ↗
Bid–ask spread
The gap between the best displayed price to buy and the best displayed price to sell. SEC ↗
Statistical arbitrage
A family of methods trading measured relative-price relationships; the name does not remove risk. SEC ↗
Strike price
The contract price at which an option’s underlying may be bought or sold under its terms. Investor.gov ↗
Survivorship bias
A distorted test that omits assets or strategies that failed or disappeared. SSRN ↗
TWAP
Time-weighted average price; an execution schedule or benchmark based on time intervals. SEC ↗
VWAP
Volume-weighted average price; an execution schedule or benchmark weighted by trading volume. SEC ↗
Definitions are educational summaries, not contract terms or investment advice.
Sources
Examples marked made-up numbers are invented. Nothing in this lesson is a recorded CouchChange result or a recommendation.
- NIST Generative AI profile
- SEC staff report on algorithmic trading
- Bailey and coauthors on backtest overfitting
- SEC investor bulletin on options
- SEC market-structure remarks on high-frequency trading
- CME introduction to managed futures
- SEC investor bulletin on crypto custody
- CFTC statement on U.S.-listed perpetuals, May 2026
- CFTC advisory on spot and futures risk
- Freqtrade lookahead-analysis documentation
- SEC-filed statistical-arbitrage prospectus
- Pyth price aggregation
- Uniswap v2 protocol paper
Try it
What is the difference between a spread and slippage?
Think it through, then open an answer
The spread is the gap between displayed buy and sell quotes. Slippage is the difference between an expected or reference price and a fill.