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MARGIN CALLv0.78.0
Free · No account · Runs in your browser

Most trading games move prices at random. This one simulates the economy that moves them.

Rates rise, so leveraged companies pay more to service debt, so earnings fall, so the price falls. That chain is modelled end to end, which is why the lessons transfer.

Sectors
12
Asset classes
7
Accounts required
0

What is actually simulated

The macro economy

GDP, inflation via the Phillips Curve, unemployment via Okun’s Law, and the Fed rate via the Taylor Rule. Each one feeds the next.

Company fundamentals

Quarterly earnings, debt service, and Merton distance-to-default, so bankruptcies happen for reasons you can see coming.

Volatility that clusters

GARCH(1,1) with a shared factor model. Quiet weeks stay quiet; correlations converge on 1 when the VIX passes 40.

Options priced properly

Black–Scholes with live Greeks and an implied-vol surface that crushes about 30% the morning after earnings.

Politics with consequences

Elections, legislation and lobbying apply real sector modifiers. A bill at floor vote is priced before it passes.

Rivals that read the cycle

Value, momentum, day-trading and raider strategies that react to volatility and the economy, not to you.

Questions people actually ask

Is it free?

Entirely. No account, no download, no payment, no ads.

Do you keep my data?

Your entire game lives in your browser. There is no account to leak, and clearing site data deletes the save permanently.

Will it teach me real trading?

It teaches the concepts: reading a chain, sizing a position, what a rate decision does to a sector. It is not advice, and it is not connected to real prices.

Does it work on a phone?

Yes, a separate touch interface, not a squeezed desktop. Any modern browser.

Is it multiplayer?

Single-player against five to ten AI rivals, depending on difficulty, plus an optional daily-challenge board.

What you can trade

Stocks · Options · Corporate bonds · Crypto · Forex · Prediction markets · Real estate

Plus founding a company, taking it public, running a hedge fund, and playing across generations.

What it runs on

Any current browser on desktop, tablet or phone. Nothing to install, nothing to sign into.

Where your save lives

In your browser, in IndexedDB. It never reaches a server, which also means clearing site data deletes it for good.

Report a bug

Report a bug
Not financial advice

Every company, price and data point is invented. Simulated results say nothing about real markets.

Release notes

Last updated 26 October 2026
v0.78.0
Current

Problems reach us sooner. When the game fails in your browser, it now sends us a short technical report so we can fix it, often before anyone has to write in. Nothing personal is in it.

An updated privacy policy. It now describes those error reports: what they contain, that they never include your save or anything that identifies you, and that they are kept for up to 90 days.

One game, one tab. Open your game in a second tab and that tab takes over: the first pauses and says so, instead of the two quietly overwriting each other's save.

v0.77.0The margin call calculator names Margin Call once in search results.October 2026
v0.76.0One tab plays a game at a time, the game opens with cookies blocked, and a failed download says so instead of leaving an empty page.October 2026
v0.75.0Starting a new game waits for your confirmation, and the game runs in browsers without WebAssembly, such as Edge with enhanced security.October 2026
v0.74.0The home page says what the game is, with the guides and calculators linked from it.October 2026
v0.73.0Your game always opens, even when browser storage stops answering, and a notice says when a game is not being saved.October 2026
v0.72.0A simpler start, and markets calibrated to decades of real data, with credit ratings and defaults drawn from real figures.October 2026
v0.71.0Free margin call and options profit calculators arrived, in every language and linked from every guide.October 2026
v0.70.0Every company started at a fair price, so the first days stopped lurching, and coach tips stopped hiding under rival messages.October 2026
v0.69.0Phones got titles that fit and a net worth that is never cut off, a trading halt started holding the price you see, and the contact form got harder to misuse.October 2026
v0.68.0Prices moved like a real market: market, sector and company factors, earnings priced once, an IPO no longer lifting every stock, and a VIX that counts each scare once.October 2026
v0.67.0Chinese, French and Spanish pages got their own addresses and search listings, and the language menu came to every page.October 2026
v0.66.0The VIX started behaving like fear, a trading ban let players wind down, the last invented research data was replaced, and the public pages became available in every language.October 2026
v0.65.0Saves, net worth, options and dividends were fixed, every chart and indicator became real, and the economy started reaching the market.October 2026
v0.64.1The language menu opened over the page instead of inside the top bar.October 2026
v0.64.0Margin Call became playable in Chinese, French and Spanish, the 5M and 1H charts kept drawing, and the order book stopped flickering.October 2026
v0.63.2A hedge fund’s seed money stopped vanishing from net worth, and the advisor stopped repeating its welcome.September 2026
v0.63.1A waiting order stopped dragging its own stock down, and a part-filled order stopped counting twice.September 2026
v0.63.0Trailing stops fire, the trade screen keeps the stock you were on, the order book sits still, and the economy stopped pinning itself to its limits.September 2026
v0.62.0The chart showed the right company, trailing orders became findable, and all eight ticker colours appeared.September 2026
v0.61.0Runs stopped ending while you still had money, saved runs survived a reload, and every skill became earnable.August 2026
v0.60.0Hedge funds, the real order book on the trading screen, and one-click screens.August 2026
v0.54.0Pausing holds what is on screen, the bell only interrupts when something happened, and starting cash is yours to choose.August 2026
v0.53.0Ordinary buying stopped drawing an investigation, lawyers became hireable, and every screen scrolls.August 2026
v0.52.0News that lands once and in full, rival desks that short, and save export back on the account page.August 2026
v0.51.0Earnings reach the price, and every company reports on schedule.August 2026
v0.50.0Short selling on desktop and phone, with the real borrow rate and margin shown before you commit.August 2026
v0.49.0End-of-day recap, rival desks in the news, and WHY IT MOVED on every stock.August 2026
v0.45.0Honest price attribution, the SEC and trade-history fixes, and release notes that publish themselves.August 2026
v0.44.0Crowd flow, fund-like rivals, whale block trades, and the card-is-the-setup homepage.August 2026
v0.43.0Stationary price model, live order book, plain-language simple mode by default.July 2026
v0.38.0Simple treatment extended across every reachable table, panel and quote view.June 2026
v0.32.0Chapters removed. The narrative beats interrupted the market rather than commenting on it.June 2026
v0.27.0Simple mode became the default and the daily challenges were retired.June 2026
v0.20.0Annual review set-piece, realised P&L on stock trades, and the realised-trades panel.June 2026
v0.19.0The Floor Amber redesign was reverted to the green-phosphor CRT terminal.June 2026
v0.8.0Command palette, named AI rivals, additional themes and save export.May 2026
v0.5.0Economy rebalanced: faster mean reversion, wider credit spreads, more bankruptcies in distress.March 2026
v0.1.0First release: 108 companies, the macro economy, the price model and founder mode.March 2026