Open source · Runs locally on your computer · For IBKR & compatible introducing brokers

The trading journal
that belongs to you.

Simply track with precision.

Consistently profitable stock and options trading needs a good trading journal. ThetaForge pulls your trades automatically from Interactive Brokers / CapTrader, computes returns on a time-weighted basis and shows what each strategy actually earns. No retyping, no spreadsheet upkeep, no subscription. Install, start, done: ThetaForge runs on your own computer, and your data never leaves it.

Install locally Open live demo

AGPL-3.0 · For Interactive Brokers and compatible introducing brokers

ThetaForge dashboard with demo portfolio: portfolio value, return, deposits/withdrawals, drawdown

Dashboard with demo portfolio (synthetic data, ~€70k).

Open sourceAGPL-3.0 – auditable down to the last formula
LocalYour data stays on your computer
Read onlyFlex Query import – no trading access
No subscriptionThe open source core is free
SecuredOptional password locally, two-factor login in the cloud
Features

Track simply and precisely with ThetaForge.

A journal answers one question: what makes you money and what does not. To do that it needs two things: to stay current on its own and to compute correctly. A journal you have to maintain by hand stops being maintained after three weeks.

Automatic Flex Query import

Trades, premiums, dividends, fees and transfers – automatically from IBKR, with no retyping and no running TWS.

Time-weighted return (TWR)

Deposits and withdrawals do not distort your performance. Calculated the way professional asset managers report it.

Strategy tagging

Covered calls, CSPs, spreads, 0DTE – assign every position to a strategy and analyse by strategy, not just by account.

Dashboards & equity curve

KPI tiles, calendar heatmap, premium history – the state of your trading at a glance.

Multi-portfolio & multi-user

Several IBKR accounts in one instance, analysed separately and viewed together. And in the cloud variant several users with their own login – family or trading partners keep their journal on the same instance, each strictly limited to their own data; locally ThetaForge is meant for one person.

Data foundation

An import that knows the edge cases.

A journal is only as good as its data. ThetaForge processes the Flex Query data relevant to the journal, including typical edge cases – exactly the rows where spreadsheets fail.

  • Account transfers, stock splits, foreign currencies are detected reliably and correctly
  • Assignments, exercises and expirations are booked as what they really are
  • Corporate actions, transfers, currencies flow cleanly into holdings and returns
  • Multi-year history via an initial import, then kept current automatically
  • A blank rather than a guess – missing data is never silently invented
ThetaForge trade journal with imported options trades, strategies and filters
Return calculation

Numbers you can trust.

On simple portfolio curves, deposits look like phantom gains. ThetaForge computes on a time-weighted basis – the way asset managers account for performance.

  • TWR, cash-flow adjusted – deposits and withdrawals distort nothing
  • IRR as a second perspective – the time-weighted return measures the strategy, the money-weighted one your actual use of capital; ThetaForge shows both
  • Drawdown analysis with depth, duration and recovery time
  • Benchmark comparison – your portfolio against SPY & co., measured honestly
  • Localised number formats in every view and every export
ThetaForge portfolio value view with time-weighted return by month
Strategy analysis

See which strategy makes the money.

A portfolio balance says nothing about whether the covered calls are working or the spreads are costing return. Only assignment by strategy makes trading manageable.

  • Free tagging – assign every position to a strategy
  • Analysis by strategy instead of just by account: premiums, win rate, result
  • Period comparisons – month, quarter, year, since inception
  • Trade journal & trade analysis as a searchable history of every decision
ThetaForge trade analysis: strategy comparison, PnL calendar, trading stats
Dashboards

Your portfolio at a glance – the way you like it.

Widgets instead of rigid reports: you assemble the dashboard that answers your questions.

  • Freely arrangeable widgets – portfolio value, premiums, heatmap, equity curve, drawdown and more
  • Portfolio value by asset class – stocks, options, cash and more, switchable between euro and dollar
  • Deposits and withdrawals in view – every capital flow captured cleanly and separated from performance
  • VIX term structure with trend detection – market sentiment at a glance, right next to your own portfolio
  • Time ranges in one click from a single week to the full history
  • Multiple portfolios viewed individually or combined
ThetaForge dashboard with portfolio value, cash ratio, return and drawdown
Security & data sovereignty

You handle your own money with care – and so does ThetaForge.

Financial data demands more than a login. The security architecture is part of the core, not an option.

  • Strictly read-only access – the Flex Query can report, never trade
  • Row Level Security in the database – every row belongs to its owner
  • Your computer, your data – stored locally, no telemetry; in the cloud variant you choose the hosting region yourself
YOUR COMPUTER app and database run locally ThetaForge app runs locally · no telemetry Your database on your own disk · Row Level Security Tokens encrypted DU Your browser on this computer password optional journal in a browser window localhost – stays on the computer YOUR BROKER Interactive Brokers CapTrader Flex Query one-way · read only no trading access No central ThetaForge server — your data stays on your computer. Optionally the same app runs in your own cloud. The data flow is one-way: the Flex Query only reports — trading access does not exist.
Try it live

Try the app in the demo portfolio.

No video, no sign-up: open the running ThetaForge instance with a synthetic demo portfolio and click through the dashboard, journal, strategy analysis and return calculation yourself. Everything is really computed, nothing embellished – just with fictional figures.

Open live demo →
Installation

How to get ThetaForge.

For Windows there is a ready-made installer: download, install, start – done. On Mac, Linux, or with the source code, ThetaForge runs just as locally via one free helper program. If you would rather work from any device in the browser, run the same app in your own cloud. All three routes load ThetaForge from the public archive.

Recommended for Windows

ThetaForge Desktop – installer for Windows

The complete app including its database runs locally on your Windows computer. No cloud account, no setup with third-party services – your trades stay on the machine. ThetaForge reaches the internet only to set itself up and to fetch your broker reports.

1

Download the setup file

The releases page on GitLab has the current version as the ThetaForge Desktop Setup for Windows, with a checksum file next to it for anyone who wants to verify it.

2

Dismiss the SmartScreen warning

Windows warns about the setup file because it is not signed. Click More info, then Run anyway, and installation continues normally.

3

Install and start

The wizard walks you through installation and sets everything up on the first start. ThetaForge then opens in a browser window – without a login. If the helper program Docker is not on the computer yet, the wizard installs it as well: the first run then takes noticeably longer, and a restart of the computer may be needed.

  • ✓All data stays on your computer – nothing leaves it
  • ✓No Vercel, no Supabase, no email account needed
  • ✓Opens without a login; a password can be enabled optionally
  • –Windows only; for Mac and Linux see below
  • –The daily import runs only while the computer is on
  • –Single user; backing up your data is up to you
Download the setup file How it works
For Mac, Linux and the source code

ThetaForge Desktop – via Docker

On Mac and Linux, or if you would rather take the source code directly: install one free helper program, download ThetaForge, run the starter.

1

Install Docker Desktop

One free helper program, once. It runs ThetaForge and its database in small isolated boxes – you never configure anything inside them.

2

Download ThetaForge

Open gitlab.com/thetaforge/thetaforge in your browser. Above the file list, on the right, is the Code button: click it, then under Download source code click zip. Unpack the file: you get a folder thetaforge-main; inside it a folder desktop, and in there the file ThetaForge starten — that is the one you need in the next step.

3

Run the starter

On Mac and Linux it is a short command from the guide; on Windows, double-click „ThetaForge starten“ – if you take the source code instead of the installer. The first start downloads the ready-built app, sets everything up and opens a browser window – without a login, entirely on your computer.

  • ✓Runs on Windows, Mac and Linux
  • ✓No Vercel, no Supabase, no email account needed
  • –Docker Desktop must be installed
  • –The daily import runs only while the computer is on
  • –Single user; backing up your data is up to you
View the source How it works
Also possible

Run it in the cloud (web version)

The same app on the free tiers of Vercel and Supabase – worth it if you want to reach the journal from several devices, invite further users, or keep the daily import running while your computer is off.

  • ✓Nothing to install, reachable in the browser from any device
  • ✓The daily import runs automatically – even when your computer is off
  • ✓Multiple devices and users possible
  • –A Vercel and Supabase account is required (the free tier is enough)
  • –Your data sits in your cloud – yours, but online
  • –Initial setup around 30–60 minutes
View the source How it works
Open source

Open source – the code is open for private use.

The licence is settled, and the archive is open.

Make it your own app

Missing a widget or an analysis that no vendor will ever build for you? Take your own fork and let your AI assistant add exactly what your trading needs – on a mature foundation instead of from scratch. No subscription product gives you that freedom.

Open source under AGPL-3.0

Every formula, every calculation is open to inspection. Forking and adapting privately is expressly allowed – the licence keeps the code free for good.

One author, a clear direction

The calculation core stays in one hand – that keeps quality and direction consistent. Bug reports are welcome. For one area, code contributions are expressly wanted too: connectors for further brokers and banks.

Name protected, code free

The word mark "ThetaForge™" is protected. The code is free – the name stands for the original and its stream of updates.

Roadmap

Status and outlook.

Available

ThetaForge Desktop for Mac, Linux and source (via Docker)

The complete app including the database runs locally via Docker – with no Vercel and no Supabase account, all data stays on the machine. For Mac, Linux and anyone taking the source code, see Installation.

Available

Web version in your own cloud

The same app on Vercel + Supabase, guide included – for access from several devices and for several users.

Planned

English interface

ThetaForge fully in English – same app, switchable language. Planned as one of the next updates, so that international traders too can use the journal in their language.

Available

Installer for Windows

ThetaForge Desktop as an ordinary Windows program: download, install, get going – the installer sets up Docker in the background by itself, no setup of your own needed. The recommended route for Windows, see Installation.

Open

Public archive on GitLab

Every version is traceable in the changelog. Suggestions and bug reports go via the GitLab issues or by email to kontakt@thetaforge.de – the roadmap is public. And if you develop yourself: connectors for further brokers and banks are expressly welcome as contributions.

About the project

Why ThetaForge exists.

Θ
westkontorAuthor & maintainer

Runs ThetaForge as an open source project and keeps developing it. Questions, feedback and bug reports are welcome by email to kontakt@thetaforge.de or via the GitLab issues.

GitLab profile →

ThetaForge is not a startup and not a subscription product. It grew out of a simple need: anyone who trades actively but has little time does not keep a journal by hand. So one was needed that maintains itself – with automatic import, correctly computed returns and analysis by strategy.

There are already several commercial trading journal solutions, but here ThetaForge has a few real distinguishing features.

The tool matured in real trading use, version after version, reconciled against real IBKR reports and their edge cases. Now the core is being opened up: open source, self-hosted, without a paywall. Development stays in one hand; that keeps quality and direction consistent.

ThetaForge is developed and maintained by its maintainer under the handle westkontor; reachable at kontakt@thetaforge.de.

FAQ

Answered briefly.

I don't know GitLab – what is it, actually?
GitLab is a widely used platform that hosts open source software – a public repository with version control. The ThetaForge archive lives at gitlab.com/thetaforge/thetaforge.
Do I need programming skills?
No. On Windows, the installer is enough: download, dismiss a Windows security warning, install, start – done, no command line at all. On Mac, Linux or with the source code it takes three steps: install a free helper program called Docker, download and unpack ThetaForge, then double-click the file „ThetaForge starten“ or run the start command – a quarter of an hour, with a command line only on Mac and Linux. If you would rather run the app in the cloud, a guide walks you through the setup at two hosting services (Vercel and Supabase, both with free plans); it lives in the archive and is available once that opens. It is even easier with an AI chat in the browser: upload the guide to Claude or ChatGPT and let it guide you – when in doubt, a screenshot and the question of where to click is enough. Expect 30 to 60 minutes the first time. If you have no idea but have at least used a PC and an AI chat before, it can also take a day. Anyone working with developer tools like Claude Code can have the setup done largely automatically. You do not strictly need that to get started – these tools have to be set up themselves first.
What is a Flex Query – and can ThetaForge access my account?
The Flex Query is Interactive Brokers' reporting interface: it delivers your account statements as a data export – nothing more. ThetaForge reads only these reports. There are no order rights, no trading connection, no way to change your account. At worst, someone with your Flex token could read your statements – they can never trade.
My account is not with Interactive Brokers – does it still work?
The automatic import is built in for Interactive Brokers; affiliated brokers such as CapTrader, LYNX or BANX use the same Flex Query interface (please check briefly in each case). Other brokers are not officially supported. But this is exactly where the open code will pay off: the data model is described in the architecture docs, and building your own CSV import for your broker's statements is a manageable weekend project with AI support – take your own fork and give your AI assistant the data model plus a sample CSV. Once your trades are in the journal, TWR, tagging and all analyses work regardless of where they came from.
What does ThetaForge cost?
The open source core is free and requires no ThetaForge subscription. Running it locally on your own computer costs nothing at all. If you choose the cloud variant, a personal journal usually fits within the free tiers of Vercel and Supabase. Additional commercial modules, integrations or support offerings may be offered separately in the future.
Where is my data stored?
In the local version, on your own disk – nothing goes to the internet. In the cloud variant, in your own database and your own hosting account, whose region you choose yourself (e. g. EU). There is no central ThetaForge server, no telemetry and no data sharing – you are the operator of your own instance.
Can I host my family on the same instance?
Yes – that is what the cloud variant is for; the local installation is for one person. ThetaForge is multi-user: registration is closed by default, and you as the operator invite further users – partner, family, trading colleagues. Each gets their own login and a fully separate journal with their own portfolios; the database itself enforces the separation (Row Level Security), and no one sees anyone else's data. A subscription journal charges per head – your instance hosts everyone together.
Is there support?
ThetaForge is provided honestly "as is": carefully built and maintained, but without a support commitment. Bug reports and feedback are welcome and feed into prioritisation – simply by email to kontakt@thetaforge.de, for which you do not need an account, or via the GitLab issues. A free project cannot offer guaranteed support; that is why it is stated so plainly here.
Can I help develop it or contribute features?
Ideas and bug reports: very welcome. Finished code for the calculation core: no – ThetaForge follows the model of projects like SQLite: the source code is open, but development of the core deliberately stays in one hand. That keeps quality consistent and responsibility clear – every line that computes your returns has gone through the same review process.

There is one exception: connectors for further brokers and banks. These import interfaces sit cleanly separated from the calculation core in their own directory, and contributions there are expressly welcome – your broker is missing and you can program? Then build it in. All that is required is an informal declaration of origin per commit (DCO, git commit -s) – no contract, no assignment of rights: your contribution stays your work under AGPL-3.0. The details are in CONTRIBUTING.md once the public archive is open.

Anyone who wants their own features beyond that may fork the project at any time and keep building it for themselves; the licence guarantees precisely that freedom.
Can't I just build this myself with AI?
You can – that is exactly how ThetaForge came about. But the lesson from building it is: the dashboard is the weekend project. The real work is where the numbers have to be right – IBKR reports with all their quirks (assignments and exercises, corporate actions, transfers, currencies, cancellation rows), a TWR that does not lie when money comes in or out, options-writer edge cases such as rolls and expiration, plus a security architecture and a test foundation with fixed reference values that checks every change against known correct results. These last 20 percent cost countless reconciliations against real IBKR reports and documented edge cases, and that is exactly what you get here for free. And if something is missing: the code is open. Fork it and build on this head start instead of starting from scratch – and turn ThetaForge into your very own app. With open source software this customisation is not a limit but the whole point.
May I use ThetaForge commercially?
The AGPL-3.0 also permits commercial use – but then requires you to publish your source code that builds on it as well. Anyone who wants to use ThetaForge in a closed product or service (e. g. as a broker, coaching provider or tax adviser) is welcome to get in touch for a no-obligation exchange about licence options: kontakt@thetaforge.de.