Market data at PatternX: sources, freshness and limits

Two engines, two kinds of data

PatternX runs two engines with different data needs. The signal engine looks for chart patterns in candles on crypto, stocks, ETFs and FX. Momentum Lab watches US stocks in extended hours and reacts to quotes. Neither works from a tick-by-tick feed, and neither watches the whole market at once.

Signal engine inputs

Candles from each connected venue

For every market you track, on every timeframe you choose, the scanner asks the venue for the latest 200 bars and needs at least 60 to scan. Timeframes run from 1m to 1d; new accounts start with 5m, 15m and 1h. The newest bar may still be forming, so a breakout can be detected on a bar that later closes differently.

Market context

The venue's ticker (last price and 24-hour volume), order book (spread and imbalance), funding rate and open interest are fetched together and reused for up to 30 seconds per venue and symbol. They drive the universal filters (spread at most 0.25%, order-book imbalance against the trade no worse than −0.5, liquidity score at least 30) and part of the PatternX Score.

Higher-timeframe candles

For the multi-timeframe check, the scanner also reads 100 bars of the next timeframe up, reused for up to 2 minutes. That input can change the score; it never rejects a signal.

Crypto liquidity rules

On crypto venues a market needs at least $3M of 24-hour volume before a signal can appear; broker markets are exempt. The crypto symbol picker offers each exchange's top 20 markets by 24-hour volume. Eight of the 40 crypto venues are spot-only and serve data, paper and manual use (crypto markets).

Broker data through your connection

Stocks, ETFs and FX have no public feed in PatternX. They are read through connected broker accounts, which is why scanning them needs your own broker connection. The traditional list holds 309 curated instruments: 123 US stocks, 67 ETFs, 62 leveraged or inverse ETFs, 29 Bitcoin and Ether ETFs and 28 FX pairs including gold and silver (traditional markets).

Cadence and venue rate limits

Markets are rescanned every 120 seconds on Free, 60 on Starter, 30 on Pro and 10 on Elite, across up to 3, 20, 100 or unlimited tracked symbols. Each market is fetched once per cycle and shared by everyone tracking it. Venues cap request rates, so PatternX limits how many markets it scans per venue per cycle and rotates through the rest, more tightly on venues with small budgets such as Hyperliquid, where the same budget also serves live position management. On a busy venue, a market can therefore wait longer than your plan's interval. Candles are reused for up to 20 seconds. When a venue answers with a rate-limit error (HTTP 429), scanning there pauses for about a minute, doubling with each consecutive round up to 20 minutes, and the first successful scan resets it. Signals on that venue can arrive late, or not at all, in the meantime.

Momentum Lab inputs

Sources and what they supply

Momentum Lab reads quotes from your own broker data: your IBKR gateway or your Alpaca account. IBKR covers premarket from 04:00 New York time. With Alpaca the feed matters: SIP is real time across all US exchanges from 04:00 but needs Alpaca's Algo Trader Plus subscription; IEX is free but covers premarket only from 08:00 and sees only trading on IEX. Polygon is a platform-level source PatternX can provide. Quotes are polled rather than streamed; with IBKR, about once a second, in step with the engine's cycle.

The consequences are concrete. Relative volume works only with IBKR data, and it is today's volume ÷ average daily volume, not adjusted for time of day, so early-premarket readings run low by construction. A VWAP confirmation can never pass on IBKR data. Halts are flagged only by IBKR.

Market cap, step by step

The market-cap gate is mandatory, so where the number comes from matters, and that depends on your data source.

• With IBKR data: IBKR's own figure (field 7289). If IBKR has none, PatternX derives one from SEC EDGAR: shares outstanding from a 10-K or 10-Q at most 200 days old, multiplied by the lower of the last price and the previous close, labelled derived. That step excludes 20-F and 40-F filers, funds, companies with a reverse-split 8-K since the filing, and anything but the main listing. Using the lower price means a gainer's figure is never inflated by the day's jump. If that cannot help either, Polygon's figure is used for common stock, where PatternX provides Polygon.
• With Alpaca data: Alpaca publishes no market cap, so the only source is PatternX's platform Polygon feed. The SEC-derived figure is not used, and where PatternX provides no Polygon feed there is no market cap at all.

A figure older than 72 hours counts as unavailable, and ETFs on PatternX's list get no figure. A missing value never passes; a trigger that arrives while the figure is still loading is held, not refused. More in market-cap filters.

The data-quality gate

Every quote must pass a gate that rejects a missing quote, a delayed feed, a missing exchange timestamp, data older than 10 seconds and a crossed quote. If the last trade prints more than 3% outside the bid and ask, the midpoint is used instead. Stale data never arms, confirms or triggers an entry; price-based exits wait for fresh data, while clock-based exits fire regardless. After 30 seconds of data failure, a breaker blocks new entries.

Movers discovery

Momentum Lab does not track the entire US market tick by tick. It pulls movers lists, 50 gainers and 50 losers per source, refreshed every 15 seconds: from IBKR's scanner (top percentage gainers and losers above $1, with a market-cap floor) or, for Alpaca, computed from a market snapshot. The top 15 per side are quoted, and at most 25 new candidates per strategy are admitted each cycle (premarket gainers and losers).

Limits to keep in mind

• No streaming or tick data. The signal engine scans candles every 10 to 120 seconds by plan; Momentum Lab polls quotes about once a second.
• The latest candle may be forming. A pattern can be detected on a bar that later closes differently.
• Delayed data is never traded. A delayed Momentum Lab feed is flagged and cannot trigger; a free IEX feed is real time but partial.
• Context ages. Order-book, funding and open-interest inputs can be up to 30 seconds old when a scan uses them.
• Venues fail. Rate limits, outages or a logged-out broker connection delay or stop scanning on that venue.
• Market caps are approximate. Derived figures rest on filed share counts, and Momentum Lab backtests apply today's figure to past days.

The Momentum Lab guide covers data entitlements, and how PatternX backtests work covers historical data.