What it is
High-frequency trading (HFT) is a specialized form of algorithmic trading characterized by its extremely rapid execution of a large volume of orders. HFT firms use sophisticated computer programs, co-located servers near exchange matching engines, and high-speed data connections to gain a fractional time advantage. They aim to profit from tiny price discrepancies across markets or by providing liquidity and capturing the bid-ask spread, executing trades in fractions of a second.
HFT significantly influences market microstructure, contributing to market liquidity but also raising concerns about fairness and stability. Its speed can exacerbate market volatility during periods of stress, potentially leading to "flash crashes" where prices drop sharply in moments. Regulators often scrutinize HFT practices for potential market manipulation or unfair advantages. Retail investors encounter HFT's effects through tighter bid-ask spreads and rapid price movements, which can affect order execution and perceived market efficiency.
Why it matters
HFT impacts market liquidity and volatility, influencing how quickly and at what price retail investors' orders are filled, and can contribute to rapid market shifts.
Reviewed under editorial standardsUpdated September 26, 2026Not investment advice