Prediction-market terminal
The edge was always in the book.
Harpoon puts every contract's full depth and every trade on your screen, live, drawn by your GPU. Now you can see it.
Why it's different
Built for speed, not for a browser tab.
Drawn on your GPU
One Rust codebase rendered with wgpu. The desktop app and the browser draw the same contract identically, frame for frame.
The whole book, unsummarised
Every price level and every trade, kept as recorded. The history you scroll back through is the market as it was.
Loads on select, never on scroll
Choose a contract and it arrives whole. Panning and zooming never touch the network, so the view never stalls on a fetch.
Scripts that run on the tape
Write a study once, then run it live or backtest it over a contract's recorded history, with the same code both ways.
Everything Harpoon will be
Every part, and where it stands.
The live terminal
Every contract, drawn on your GPU, updating as fast as the market moves.
In developmentOrder-book heatmap
See resting liquidity build and vanish at every price, through time.
In developmentEvery trade of a contract's life
Open a contract and see its whole history, from a tape that is never rewritten.
In private testingThe Finder
Search any contract by name, or browse sport → game → market.
In developmentScripts
Write your own indicators and studies, and run them on any contract.
In developmentBacktests
Run a script over a contract's recorded history before you trust it live.
In developmentScript library
Publish your scripts, subscribe to others', install with one click.
In developmentAlways-on alerts
Get a message when something you care about happens, with your computer off.
In developmentIn your browser
The same terminal in a browser tab, nothing to install.
In developmentWindows and Mac apps
A native app for Windows and for Mac, from one codebase.
Coming soonMore venues
More prediction-market venues, side by side in one terminal.
The terminal
See it for yourself.
The book, as a heatmap
Liquidity at every price, through time.
The Finder
Sport → game → market, or type any letter.
A contract's tape
Every trade of its life, as it happened.
Who it's for
For the people who read the book.
Serious traders
You trade event contracts often and the venue's own app has stopped being enough.
Quants and script writers
You want the raw tape, a real scripting language and backtests on the real history.
Sports-market specialists
You need the right game and the right market in two keystrokes, while the game is live.
Questions
Asked and answered.
What is Harpoon?
A trading terminal built for prediction markets. It draws every contract's order book and every trade on your GPU, live, and lets you script, backtest and get alerted on what you see.
Who is it for?
Traders who take event contracts seriously, quants and script writers who want the raw tape, and sports-market specialists who need to find the right game and market in seconds.
What does it cost?
Nothing while it is in private testing. Plans come when it opens, and the pricing page will say what each includes.
Which platforms?
Windows is in private testing now. The browser terminal and the Mac app are in development, drawn from the same code.
Does Harpoon place trades?
Today Harpoon is for viewing and analysis. It never holds your money.
Which markets does it cover?
US prediction markets, starting with one regulated venue. More venues follow, each in the same form, so one script works across all of them.
How do I sign in?
With your email and a one-time code. There is no password to leak.
When can I get in?
We don't give dates. Join the early-access list and we'll write when there is a place for you.
Get early access
Harpoon is in private testing. Leave your email and we'll write when there is a place for you.