Credential pair (public & private) used to authenticate programmatic access. Use sandbox keys for development; never commit live secrets to source control.

Protocol (e.g., Uniswap) that prices assets via liquidity pools and a formula (e.g., x*y=k) instead of a central order book.

Strategy exploiting price differences between markets or instruments; must cover fees/slippage to be profitable.

Lowest price a seller will accept; the counterpart to the bid price.

A bet supporting an outcome to happen — like ‘buy’. On Betfair a back wins if the selection wins; stake × (odds − 1) = potential profit.

Highest price a buyer will pay; together with ask defines the spread.

Capital allocated to a strategy; used to compute position sizes and set risk limits.

Running a strategy on historical data to estimate performance; must include realistic fills, slippage, and fees.

Difference between best ask and best bid; an immediate cost to cross the market.

Open/High/Low/Close bar representing price movement in an interval; building block for many indicators.

Unique token attached to an order to allow safe retries without duplicate fills; essential for automation.

Body shows open-close range; wick (shadow) shows intrabar extreme prices. Useful in pattern recognition.

Custody is asset management. Hot wallets are online for frequent use; cold wallets are offline and more secure for long-term storage.

Private trading venue where orders are not publicly displayed; used for large block trades to reduce impact.

Instrument deriving value from an underlying asset (futures, options, perpetuals).

Process of releasing code; for bots include secrets handling, monitoring, and rollback/kill-switch plans.

Repeatable advantage or rule that produces positive expected value after costs.

EV = (WinRate × AvgWin) − (LossRate × AvgLoss). Positive EV (after fees/slippage) grows capital over time.

Execution that fills an order wholly or partially. Partial fills require handling for remaining quantity.

Charges by exchanges, brokers or networks (maker/taker, withdrawal fees); include fees in backtests and EV calcs.

Periodic payment between longs and shorts in perpetual swaps to anchor price to index; affects carry cost of positions.

Fees paid to miners/validators to include transactions on‑chain (e.g., Ethereum gas); important for cost modeling on blockchain strategies.

Price jumps between observations (e.g., overnight) that can bypass stop-loss orders and create stress scenarios.

Order duration remaining active until executed or cancelled (exchange semantics may vary).

Periodic liveness signal indicating the system/component is alive; used in monitoring and alerting.

Online wallet for active transactions; more convenient but higher security risk than cold storage.

Property where repeated identical requests have the same effect as a single request; avoids duplicate orders on retries.

LP loss in AMMs relative to holding the assets due to price divergence; fees and incentives can offset it.

Tradable asset (e.g., BTC‑USD, SP500 futures, MATCH_ODDS selection) or contract being traded.

Sudden large price moves that can cause slippage and stop bypass; factor into stress testing.

Formula to maximise long‑term growth given edge and win probability; often scaled down for risk control.

Availability of volume at or near current prices; low liquidity increases slippage and market impact.

Forced closing of positions when margin requirements fall below maintenance levels; avoid by monitoring margin and reducing leverage.

Maker adds liquidity (limit orders); taker removes liquidity (market orders). Fee schedules often differ for each role.

Price effect caused by executing orders; larger orders and thinner books increase impact and realized slippage.

Key Betfair fields: AvailableToBack/AvailableToLay (price ladders), SizeMatched (per runner), TotalMatched (market volume matched).

Pool of pending on‑chain transactions waiting to be included in a block; affects latency and MEV vectors.

Value miners/validators/actors can extract by reordering or including transactions (frontruns, sandwich attacks) in blocks.

Per‑account transaction counter preventing replays and ensuring correct ordering on chain.

Service providing off‑chain data (e.g., price feeds) to smart contracts; centralization and manipulation risk matter.

Representation of current bids and asks at price levels; order book depth informs liquidity and potential impact.

Derivative without expiry that uses funding payments to tether contract price to an index (common in crypto derivatives).

Rules to determine quantity to trade given bankroll, risk fraction, and stop‑loss distance (fixed fraction, Kelly fraction, fixed size).

Realized or unrealized profit and loss of trades; track per trade and aggregated for strategy performance.

Age of market data; stale quotes can lead to wrong trade decisions in fast markets.

Comparing expected orders/fills to exchange records to detect and correct mismatches; essential for accounting and recovery.

APIs impose rate limits; use exponential backoff and jitter to retry safely and avoid bans.

Difference between intended execution price and the actual fill; increases with order size or market volatility.

Risk‑adjusted return metric: (mean return − risk‑free rate) / standard deviation of returns.

Order or rule exiting a losing position at predefined price to limit losses; may gap in fast markets.

Simulated environment to test strategies and order flows without risking real funds; always validate end‑to‑end here first.

Collection of logs, metrics and traces to understand system behavior, diagnose issues and measure SLAs.

Execution algorithms slicing orders across time (TWAP) or by volume (VWAP) to reduce market impact.

Blockchain asset. ERC‑20 is the Ethereum fungible token standard enabling transfers and approvals used widely in DeFi.

Profit or loss on open positions not yet realized; important for margin and risk computations.

Use UTC timestamps in logs and reconciliation to avoid ambiguity across exchanges and regions.

Measure of price dispersion; implied vol reflects market expectations; realized vol is historical and used in sizing risk.

Volume‑weighted average price; used as a benchmark for execution quality.

Wallet holds keys for on‑chain accounts. HD wallets generate addresses from a mnemonic seed; manage keys securely and separate hot/cold use.

Self‑trading creating artificial volume; often illegal and distorts market data used for models.

Newly deployed instance; restrict exposure and monitor metrics until stable.