# High-Frequency Trading

> High frequency trading uses extreme speed to trade huge volumes for tiny profits per trade. Learn the main HFT strategies, the technology and the criticisms.

Source: https://learn.tradelabsai.com/algo-trading/high-frequency-trading/  
Track: Algorithmic Trading · Level: Intermediate · Updated: 2026-10-03  
Publisher: TradeLabs AI (https://tradelabsai.com). Education, not financial advice.  
Cite as: TradeLabs Learn, "High-Frequency Trading", https://learn.tradelabsai.com/algo-trading/high-frequency-trading/

High frequency trading (HFT) is a form of algorithmic trading that uses very fast computers, low latency connections and sophisticated software to trade large numbers of orders in fractions of a second. HFT firms typically hold positions for seconds or less, end the day with little inventory and earn tiny profits on each trade, adding up across millions of trades. HFT firms are major liquidity providers in modern markets, and their role has been debated since the 2010 Flash Crash and the 2014 book "Flash Boys".

## Key characteristics

| Feature | Detail |
|---|---|
| Holding period | Microseconds to minutes |
| Order volume | Very high, with many cancellations |
| Profit per trade | Fractions of a cent per share |
| End of day positions | Usually flat |
| Technology | Co location, custom hardware, optimised networks. See [Co-Location](https://learn.tradelabsai.com/infrastructure/co-location/) |
| Main edge | Speed, scale and low costs |

## Main HFT strategies

| Strategy | Description | Lesson |
|---|---|---|
| Market making | Continuously quote bids and offers, earning the spread and exchange rebates | [Market Making](https://learn.tradelabsai.com/strategies/market-making/) |
| Latency arbitrage | Exploit tiny price differences between venues that last microseconds | [Arbitrage Strategies](https://learn.tradelabsai.com/strategies/arbitrage-strategies/) |
| Statistical arbitrage | Trade short lived relationships between related instruments, such as ETFs and their components | [Statistical Arbitrage](https://learn.tradelabsai.com/strategies/statistical-arbitrage/) |
| Event and news trading | React to data releases and headlines faster than others | [News Trading](https://learn.tradelabsai.com/strategies/news-trading/) |
| Order flow prediction | Anticipate short term price moves from order book changes | [The Order Book and Market Depth](https://learn.tradelabsai.com/market-structure/the-order-book-and-market-depth/) |

## The speed race

HFT firms compete on latency, the time it takes to receive data, decide and send orders:

- **Co location:** placing servers inside exchange data centres. See [Co-Location](https://learn.tradelabsai.com/infrastructure/co-location/).
- **Microwave and laser networks:** between Chicago and New York, microwave links cut round trip times compared with fibre, because signals travel faster through air than glass.
- **Hardware acceleration:** FPGAs and specialised network cards. See [FPGAs and Hardware Acceleration](https://learn.tradelabsai.com/infrastructure/fpgas-and-hardware-acceleration/).
- **Kernel bypass and optimised software.** See [Kernel Bypass and Low-Latency Networking](https://learn.tradelabsai.com/infrastructure/kernel-bypass/).

**Example: The value of microseconds**
Spread Networks completed a fibre optic line between Chicago and New York in 2010 that cut round trip latency to around 13 milliseconds, reportedly at a cost of about $300 million. Within a few years, microwave networks offered round trips under 9 milliseconds. Shaving a few milliseconds mattered because firms trading futures in Chicago against stocks in New Jersey could act on price moves before slower competitors. See [Latency in Trading](https://learn.tradelabsai.com/orders/latency-in-trading/).

## Effects on markets: the evidence

| Effect | Findings (mixed) |
|---|---|
| Bid ask spreads | Many studies found spreads narrowed as electronic and HFT market making grew |
| Liquidity | More quoted liquidity in normal times; concerns it can vanish in stress |
| Price discovery | Some research finds HFT helps prices incorporate information faster |
| Volatility and flash crashes | HFT was involved in events like the 2010 Flash Crash, though not identified as the sole cause. See [The 2010 Flash Crash](https://learn.tradelabsai.com/history/the-2010-flash-crash/) |
| Costs for long term investors | Debated; lower spreads help, but some argue HFT extracts value from large orders |

## Criticisms and regulation

- **Phantom liquidity:** quotes that disappear when needed.
- **Speed advantage fairness:** Michael Lewis's "Flash Boys" (2014) argued that some HFT strategies took advantage of slower investors.
- **Manipulative practices:** spoofing and layering are illegal; several traders and firms have been prosecuted. See [Spoofing and Layering](https://learn.tradelabsai.com/industry/spoofing-and-layering/).
- **Responses:** speed bumps (such as IEX's 350 microsecond delay), order to trade ratio limits, minimum resting times and circuit breakers in some markets.

## Can individuals do HFT?

Realistically, no. True HFT requires large investments in technology, exchange connectivity and market data, plus specialised talent. Individual traders compete better at longer horizons where speed matters less. See [Day Trading](https://learn.tradelabsai.com/strategies/day-trading/) and [Swing Trading](https://learn.tradelabsai.com/strategies/swing-trading/).

## Frequently asked questions

### What is high frequency trading?

A form of algorithmic trading that uses extreme speed to trade very large numbers of orders, holding positions for seconds or less and earning small profits per trade.

### Is high frequency trading good or bad for markets?

Evidence is mixed: HFT has been linked to tighter spreads and more liquidity in normal times, but critics argue liquidity can vanish in stress and that speed gives unfair advantages.

### Can retail traders compete with HFT?

Not on speed. Retail traders do better with strategies at longer horizons where milliseconds do not matter.

Next, learn how algorithms are built and tested in [Developing, Testing and Monitoring Algorithms](https://learn.tradelabsai.com/algo-trading/algorithm-development/).

## Continue learning

- Next lesson: [Developing, Testing and Monitoring Algorithms](https://learn.tradelabsai.com/algo-trading/algorithm-development/)
- Previous lesson: [Execution Algorithms vs Alpha Algorithms](https://learn.tradelabsai.com/algo-trading/execution-algorithms/)
- Related: [Execution Algorithms vs Alpha Algorithms](https://learn.tradelabsai.com/algo-trading/execution-algorithms/): Execution algorithms split large orders into smaller pieces to reduce market impact. Learn VWAP, TWAP, POV and implementation shortfall algos and how to choose.
- Related: [Latency in Trading](https://learn.tradelabsai.com/orders/latency-in-trading/): Latency is the delay between a market event and your reaction to it. Learn the sources of trading latency, how it is measured and when it matters for your trades.
- Related: [Market Making](https://learn.tradelabsai.com/strategies/market-making/): Market making quotes both a buy and a sell price to earn the bid ask spread. Learn how market makers manage inventory, adverse selection and risk.
- Related: [Co-Location](https://learn.tradelabsai.com/infrastructure/co-location/): Co location places trading servers inside or beside an exchange's data centre to cut latency. Learn how it works, what it costs, fairness rules and who needs it.
- Related: [The 2010 Flash Crash](https://learn.tradelabsai.com/history/the-2010-flash-crash/): On 6 May 2010, US stocks plunged and rebounded within about 36 minutes. Learn what happened, the role of a large futures sale and HFT, and the rules that followed.
- Related: [Kernel Bypass and Low-Latency Networking](https://learn.tradelabsai.com/infrastructure/kernel-bypass/): Kernel bypass lets trading software read network packets straight from the network card, skipping the operating system. Learn how it works and the trade offs.