Published 2026-10-27
High-frequency trading
Trading that relies on speed, holding positions for seconds or less. A subset of quantitative trading, not a synonym for it.
On this page
What it is
High-frequency trading is trading where the edge comes from speed — reacting to market events faster than other participants, and holding positions for seconds or less.
The holding period is the tell. If a strategy is flat by the end of the day, it is not high-frequency no matter how fast the code runs.
The line in China is a number
Since 2025-07-07, the Shanghai, Shenzhen and Beijing exchanges’ implementing rules define high-frequency trading by count:
| Threshold | Value |
|---|---|
| Orders + cancels per second, single account | 300 or more |
| Orders + cancels per day, single account | 20,000 or more |
Cross either line and the account is treated as high-frequency, which brings extra reporting duties, different abnormal-trading standards and different fees.
Why it is not the same as quant
High-frequency is a subset of quantitative trading, and a small one:
- The edge is speed, not prediction. An HFT firm does not need to know where the price is going; it needs to be first at the moment it moves.
- Most quantitative strategies are not high-frequency. A model that rebalances monthly is quantitative and has nothing to do with microseconds.
- Conflating them is a sales move. “AI quant” sounds like front-running if you assume it means HFT. It usually does not.
High-frequency is one category inside the programmatic trading rulebook, and the smallest by account count.
Why it matters for AI quant
A language model is not in the millisecond decision path and never will be. Any product claiming to use an LLM for high-frequency trading has either misunderstood one of the two terms, or is hoping you will.
The realistic role of AI in quant is at the slow end: reading filings, screening candidates, drafting hypotheses, writing and checking code. All of it happens on the scale of minutes to days — see transaction cost for why speed stops mattering at that horizon.
How to check
Ask one question: how long is a position held?
Seconds or less, with a speed-based story — high-frequency. Days to weeks, with a signal-based story — ordinary quantitative trading. If the answer is “it depends”, they are describing neither.