Prediction market terms
Plain-English definitions for every technical term Orrery uses. Designed to be quotable — each entry is self-contained and citation-friendly.
Implied probability
The market's collective estimate of an outcome resolving YES, derived from the price of the YES share. A YES share trading at $0.62 implies a 62% probability. On Polymarket, prices range from $0.01 to $0.99 (clamped from 0 and 1 for orderbook stability).
CLOB
Central Limit Order Book. Polymarket's matching engine — buyers and sellers post limit orders for YES or NO shares; the engine matches bids and asks at the spread. Different from an AMM (constant-product). Polymarket's CLOB API exposes the orderbook and 1-minute price history per token.
UMA optimistic oracle
Polymarket's settlement layer. After a market's end date, a UMA proposer asserts an outcome with a bond. If no one disputes during the challenge window, the assertion settles. If disputed, UMA tokenholders vote. Markets in `proposed`, `disputed`, or `challenged` state should be treated as unresolved — Orrery surfaces this on the per-market page.
Conditional token
An ERC-1155 token representing a share of a binary outcome (YES or NO) on Polymarket. Each market has two tokens; together they always sum to $1. Identified by a `conditionId` plus an `outcomeIndex` (0 = YES, 1 = NO).
Spread
Difference between the best ask and best bid on the orderbook, expressed as a percentage of mid-price. A wide spread means low liquidity — moves carry less informational weight.
Liquidity
Total USDC depth in the orderbook within a reasonable distance of mid-price. Used as a denominator for almost every Orrery calculation: signal confidence is dampened on illiquid markets, Edge Score subtracts spread × 50, and the scanner offers a `liquidity>` filter.
Volume (24h vs lifetime)
Volume is the total USDC traded on a market. `volume24h` is the rolling 24-hour window; `volume` (without suffix) is lifetime. Orrery uses 24h volume as the primary heat metric and lifetime as a maturity check.
Δ24h
Change in implied probability of YES over the last 24 hours, expressed in percentage points (pp). A move from 50% → 55% is +5pp, NOT +10%. Orrery displays Δ in pp throughout to avoid the percentage-of-percentage confusion.
Momentum signal
Fires when the 1h and 24h price changes share the same sign and the 1h move is at least 1pp. Confidence = min(|Δ1h| × 8, 0.95) × liquidity factor. A momentum signal describes that a price is continuing to move in the same direction at multiple horizons — it does not predict that the move will continue.
Divergence signal
Fires when the 1h and 24h price changes have opposite signs AND |Δ1h| ≥ 1pp AND |Δ24h| ≥ 1pp. Confidence = min(|Δ1h| × 6, 0.85) × liquidity factor. Describes a short-term move running counter to the 24h trend — not a prediction of reversion.
Flow signal
Fires when ≥ 3 trades ≥ $5,000 hit the same market within the recent window AND ≥ 70% are on the same outcome. Indicates concentrated wallet activity in one direction. Confidence weighted by unique-wallet count.
Resolution risk
A signal that fires when settlement is uncertain — UMA in proposed/disputed/challenged state, or the resolution source extracted from the description is `ambiguous`, or the market is < 24h from end with probability still in the 5–95% range. Tagged with severity. NOT a directional signal.
Edge Score
Composite ranking used on /opportunities. Formula: signal_confidence × 100 + multi_kind_bonus + log10(liquidity) × 5 − spread_pct × 50 − resolution_risk × 30. Normalised to 0..100 within the result set. Multi-kind bonus is +20 if two non-resolution-risk signals fire on the same market.
Evidence tier
Live confidence of a signal at the moment it's read — `low | medium | high`. Comes from the rule's own confidence formula. Distinct from Backtest tier (historical edge). A `high` Evidence with `weak` Backtest means the rule is firing strongly right now but historically didn't generate a usable edge.
Backtest tier
Historical edge of a signal kind from a 1-month CLOB-based replay. Tiers: `strong` (win rate > 60% on ≥ 50 samples), `mixed` (50–60%), `weak` (< 50%), `forward-only` (no snapshot store yet — currently flow / resolution_risk / news_lag).
Action tier
What Orrery recommends doing with a signal. Always one of: `Watch only` / `Inspect timeline` / `Create alert` / `Verify source` / `Ignore — too noisy`. Computed from Evidence × Backtest. Never `Buy` or `Sell` — Orrery does not recommend trades.
Smart money
Working definition: wallets whose recent activity is large enough ($5K+ trades) to move price and whose history shows a positive PnL across multiple resolved markets in the last quarter. Not a signal itself — Orrery surfaces flow and lets you read the quality score per wallet.
Whale
Loose label for any wallet whose single trade exceeds $10,000. The /whales feed shows raw trades above this threshold. Whale ≠ smart money — many large traders have negative PnL.
Quality score (per wallet)
0–100 composite of: open size (notional), breadth (markets touched), ROI on closed markets, win rate on closed markets, category specialisation (a generalist with high breadth scores higher than a single-market punt). Stored as a derived field on /wallets/{address}.
Watchlist (since-last-visit deltas)
User's tracked markets, stored client-side in localStorage. The Dashboard shows price changes since the user's last visit — Orrery snapshots prices into the watchlist record on every page render so the comparison is always against "the last time you saw this market".
x402
An HTTP-native payment protocol for autonomous agents. Orrery's paid intelligence endpoints under /api/x402/v1/* return HTTP 402 with a JSON challenge specifying USDC price + accepted networks (Base). Agents pay with the X-PAYMENT header. Currently in preview mode (free during marketplace review).
MCP
Model Context Protocol. Anthropic's open standard for connecting Claude Desktop / Cursor / Claude Code / any custom agent to external services via JSON-RPC 2.0 over HTTP. Orrery's MCP endpoint at /api/mcp/v1 surfaces 18 prediction-market tools. One config line and the agent has access.
Brief / Daily Brief
Orrery's morning one-page intelligence summary at /brief. Covers biggest moves, unusual volume, signals, smart-money flow, events ending today, and resolution risk. Free, RSS at /brief/rss.xml, machine-readable Markdown at /brief/markdown.
Want the math behind the signals? /methodology spells out every formula. Want the agent-facing reference? /llms-full.txt.