Glossary

Market Data Glossary

Understand ticks, candles, Level 2 and rate limits before you integrate a market data API.

What Is Tick Data

A tick is the smallest granularity of market activity. HFT and microstructure research depend on tick streams rather than candles alone.

Knowing OHLCV semantics is required for corporate actions, indicators and cross-vendor alignment.

Channel choice affects latency, bandwidth and complexity — not just subscription price.

Latency is path-dependent. Build repeatable benchmarks from your production region.

Dashboards usually need Level 1. Market making and impact analysis need depth.

Auth and quota handling must be rock solid — especially on volatile tape days.

Backtests must declare whether candles are adjusted; otherwise return curves lie.

History backfills must be fast without tripping rate limits — pagination and concurrency matter.

Without heartbeats, long-lived sockets die silently until the next send fails.