The interactive HFT atlas · current to 2026

The interactive atlas of how high-frequency trading actually works.

Every concept you can poke. Every concept laddering up to how it makes money, in equities, crypto and prediction markets. Honest about what’s still alpha and what’s already dead.

HFT Book is a free, interactive reference on high-frequency and quantitative trading. Each idea (the order book, market making, latency arbitrage, optimal execution) comes with a live illustration you can manipulate until it clicks, links showing how it fits the wider machine, and a plain 2026 read on whether the edge still exists.

Free, no account, no paywall. Maths shown – intuition first, derivations optional. Every figure dated and sourced. Educational only; not investment advice.
Live order bookteaserIX-LOB
pricedepthsize
100.01
1,074
100.02
898
100.03
707
100.04
881
100.05
940
100.06
493
100.07
296
100.08
407
spread0.02mid 100.000
99.99
1,002
99.98
1,091
99.97
953
99.96
631
99.95
378
99.94
712
99.93
477
99.92
533
This is a teaser. Trade against the full book
What this is, and how to use it

One navigable atlas, not a paywalled paper or a dead blog.

Most explanations of HFT are a paywalled paper, a 2011 textbook PDF, a dead blog, or a thin listicle. This is the alternative: one atlas where every concept is explained clearly, shown moving wherever it can be, connected to everything it touches, and dated honestly to 2026. Read it top to bottom, or drop in anywhere.

Read a thread, not a wall.

Every page ends with a “Where this fits” block: what it’s a building block of, what it composes with, where it makes money, and the tool you’d need. Follow the up-links and you climb the money ladder.

See the whole machine.

The concept map shows every idea and how it connects, with the money-ladder paths highlighted. Start there if you want the shape of the field before the detail.

Manipulate, don’t just read.

Where a concept can be shown moving, there’s a live widget: trade against a book, blow up a market-making model, run a latency race. Understanding by manipulation.

New here? Start with the learning paths
The signature feature

This is what HFT looks like when you can see all of it at once.

Every node is a page; every edge is a link you can follow. The bright path is the money ladder: how a fair-value estimator becomes a market-making business.

The concept mapteaserIX-MAP
Open the full map
The brand's central promise

Every concept ladders up to how it makes money.

The thing missing from every textbook: how does this actually make money? Here, every concept answers it. A fair-value tweak ladders up into a market-making strategy, ladders across into three markets, and ends in the data and code you'd need to run it.

Every page on the site carries its own rung of a ladder like this. Follow the up-arrows and you’re never lost.

The field, in ten chapters

Each is a hub that links down to every concept inside it.

Browse everything on the map
Show, don't tell

Reading about a concept tells you what it is; moving it tells you why it matters.

Twenty-eight of these across the atlas. Here are three that span the field: a fair-value estimator, a market-making model you can blow up, and a latency race.

The micropricedrag the queuesIX-MICROPRICE
Best bid100.0000
Best ask100.0200
Simple mid100.0100
Microprice100.0100
Imbalance0.500
bid queue1,500ask queue1,500100.0000100.0200midmicroprice
Bid queue size1,500
Ask queue size1,500

What to notice. Make the bid queue heavier and the microprice slides toward the ask: trades are then more likely to lift the offer than hit the bid. The simple mid never moves; the microprice leans toward where price is about to go.

Open The microprice
Avellaneda–Stoikov quotinglive simulationIX-AS
Inventory q+0
Mark-to-market P&L+0.0
Half-spread0.651
Statecontrolled
inventory (centred at 0)
P&L
Risk aversion γ0.12
Volatility σ0.9

What to notice. Crank γ down toward zero: the spread collapses, fills come fast, and the reservation price stops skewing, so inventory random-walks away and the P&L lurches. Market making is an inventory-risk problem, not a spread-capture freebie.

Open Avellaneda–Stoikov
The latency racetap raceIX-LATENCY
Your speed edge30%
Win probability64%
Last race
you (fast path)competitor (slow path)stale quote
Your latency advantage30%

What to notice. Latency arbitrage isn't cleverness; it's being first to the same obvious trade. Drop your edge toward zero and it's a coin flip; in mature equities the winner already owns the fastest path, which is why it's a commoditised arms race, not an open opportunity.

Open Latency arbitrage
Apply across markets

The institutions don't travel between markets. The maths does.

See how techniques port across markets
The honesty + currency moat

Is it still profitable in 2026? We say so when the edge is gone.

Most material on HFT is years out of date and quietly oversells edges that are long gone. We don't. Every technique carries a plain 2026 read (still alpha, commoditised to a utility, dead, or structural) plus what AI changes about it.

Structural
microstructure itself – the terrain doesn’t decay
Commoditised
naive latency arbitrage – an arms race, margins compressed
Still alpha (narrow)
order-flow signals on under-modelled venues
Mostly dead
simple technical “HFT signals” sold to retail
The only ask on this page

Coming: the data and tools to actually run this.

Once a concept clicks, the next thing you want is to run it: against real book data, in an honest backtest, with reference code that reproduces the maths on the page. We're building exactly that: clean L2/L3 order-book datasets, a backtest harness, and tested reference implementations. Nothing's for sale yet.

See the planned datasets & tools
Infrastructure, never signals. No price, no urgency, no spam. We email you about the thing you waited for, and the occasional substantive new piece. Easy unsubscribe.
The questions a cold arrival actually asks

Frequently asked questions

What is high-frequency trading (HFT)?
HFT is automated trading that competes on speed and order-book microstructure: a machine quotes, cancels and executes in microseconds-to-milliseconds, typically holding positions for seconds or less and ending most days near flat. It is a subset of algorithmic trading defined by latency sensitivity and very high message rates, not by any single strategy. Read more →
What’s the difference between HFT, algo trading and quant trading?
Quant trading uses mathematical models to decide what to trade (any horizon). Algorithmic trading automates how an order is executed. HFT is the latency-sensitive corner of both: quant signals plus algorithmic execution run fast enough that microseconds and queue position decide the P&L. All HFT is algo and quant; most quant and algo trading is neither fast nor HFT. Read more →
Do I need a PhD to do quant or high-frequency trading?
No. You need strong probability, statistics and programming, and real microstructure understanding; a PhD signals those but is not the gate, especially for independent crypto and prediction-market work. Sell-side HFT desks often prefer them; an open venue does not check credentials. This site front-loads the maths so the prerequisite is competence, not a certificate. Read more →
Do I need colocation, or can I trade from a laptop?
It depends on the strategy. Pure latency races need colocation and often FPGAs; a laptop cannot compete. But slower microstructure strategies (inventory-aware market making on a single venue, statistical arbitrage, mid-frequency order-flow signals) are runnable from a laptop, especially in 24/7 crypto and prediction markets where the latency arms race is younger. Read more →
Is high-frequency trading legal?
Yes. HFT is legal and a large share of regulated-venue volume. What is illegal is manipulation (spoofing, layering, momentum ignition, quote stuffing) prohibited under the US Dodd-Frank Act §747, the EU Market Abuse Regulation (MAR, 2014) and MiFID II (2018). The technology is lawful; specific manipulative intent and conduct are not. Read more →
Is high-frequency trading still profitable in 2026?
As an industry, yes, but margins have compressed for over a decade and aggregate HFT revenue is far below its 2009 peak. Pure speed in mature lit equities is a commoditised, capital-intensive utility dominated by a few firms. The live edge in 2026 sits in newer or fragmented venues (crypto, prediction markets) and in smarter microstructure signals, not raw latency. Honest status: structural, but not the open frontier it was. Read more →
All questions