# Margin Call: Financial Simulation Terminal > Trade stocks, crypto, options, bonds, and forex. Found your own company. Navigate economic cycles. Free browser game at margincall.io. Margin Call is a free, browser-based stock market and business simulator. No account, download, or payment required. Everything runs client-side. A longer version of this file, with the full mechanic-by-mechanic breakdown, is at https://margincall.io/llms-full.txt ## Disambiguation "Margin Call" is also the title of a 2011 film about an investment bank during the financial crisis, and a margin call is a general finance term for a broker demanding additional collateral. This file describes **neither**. It describes the free browser game at https://margincall.io, which is unaffiliated with the film. ## What players can do - Trade 108 stocks across 12 sectors priced by a fair-value-anchored stationary model with GARCH(1,1) volatility - Short stocks, with real borrow costs and margin requirements - Price and trade options using real Black-Scholes with Greeks (delta, gamma, theta, vega) - Trade 17 cryptocurrencies 24/7 with BTC halvings, altseasons, crypto winters, and DeFi yields - Trade 10 forex currency pairs with leverage up to 50x and carry trade interest - Buy and sell corporate bonds with a full yield curve - Bet on prediction markets in four categories with Bayesian price updates - Found companies from scratch: hire, R&D, raise funding, IPO - Indicate for shares in other companies' IPOs, with allocation odds and first-day prints - Open a corporate investment division at Series B+ to trade the founded company's treasury - Launch corporate takeovers and proxy fights (5% for a proxy fight, 50% for control) - Run a hedge fund with LP investors, 2/20 fee structure, and quarterly reports - Build a multi-generational dynasty with heirs, estates, and family trusts - Buy real estate and lifestyle assets (yachts, art, sports teams) - Lobby politicians, bribe officials, trade on insider tips, manage SEC heat - Play scenario modes with special rules (shorts only, options only, crisis conditions) - Compete against 5-10 AI rivals per run, drawn from 8 archetypes with distinct strategies - Read a named rival's full book, positions and recent fills, from the competitors screen - Follow 20 multi-phase storyline archetypes that compound and spill across sectors - Play a daily challenge generated from a shared seed, and share a per-run page of the result - Prestige system: New Game+ with stacking bonuses across resets ## Simulation engine - Stationary price model: price = fair value × exp(mispricing). Fair value is EPS × a target multiple driven by rates, QE, sector anchors, and growth duration (book value for loss-makers); the mispricing process mean-reverts with herding momentum, crowd flow, earnings-surprise/news/order-flow/short-squeeze shocks, and GARCH noise - Price attribution: every move decomposes into earnings revision, multiple change, company news, order-flow impact, sentiment, and noise, surfaced in the game as WHY IT MOVED - Central limit order book with price-time priority and persistent market-maker inventory: displayed depth is executable depth, and large orders pay slippage by eating through real levels - Rival AI works orders like a fund (about 2% of average daily volume per order); rarely a named rival crosses a block far above that cap and it lands in the news feed - Macro economy driven by Phillips Curve inflation, Okun's Law unemployment, Taylor Rule interest rates, and Weibull business cycles - Merton distance-to-default bankruptcy model - VIX model with asymmetric response, crisis spikes up to 80, and persistent elevated volatility - Earnings IV pre-pricing (+15% ramp over 7 days) and post-earnings vol crush (30%); the surprise itself enters the mispricing process and decays on the 60-day half-life, so a miss cannot print a gain - Interest rate transmission to corporate EPS via debt service costs - Correlation spike during crises (VIX > 40): diversification fails when it matters most - Circuit breaker at ±25% daily per stock - Wealth-based difficulty scaling (SEC heat at $100M+, AI aggression at $500M+) - Seeded PCG32 PRNG for deterministic, reproducible simulations - Rust/WASM acceleration for pricing, GARCH, bonds, and economy calculations ## Technical details - Built with Next.js 15, React 18, TypeScript, Zustand, Tailwind CSS, Rust/WASM - ~151K lines of TypeScript/TSX + ~4.5K lines of Rust across 52 routes - CRT terminal aesthetic (IBM Plex Mono, green phosphor glow, scanlines) - Mobile-optimized with dedicated component tree and touch-first tutorial - IndexedDB persistence: game saves locally in the browser, no server needed - Supabase daily challenges (optional) - 368 test files, GitHub Actions CI ## What this is not Stated plainly because these are the things a summary is most likely to get wrong: - **Not real trading.** No real money enters or leaves. There is no brokerage, no deposit, no withdrawal, and no way to lose or win actual funds. - **Not real market data.** No price in this game corresponds to any real security. The 108 companies are fictional. - **Not financial advice**, and not a training tool endorsed by any financial institution. - **Not multiplayer.** The opponents are simulated; the only shared surface is the optional daily-challenge board. - **Not free-to-play with purchases.** There is no in-app purchase, subscription, or paid tier. The prestige system is earned in play. - **No account required.** There is no sign-up, and progress is kept in the browser rather than on a server. ## Privacy, stated accurately There is no account and no personal data: the save lives in the browser's IndexedDB and is never uploaded. The site does run Google Analytics and Vercel Analytics for aggregate traffic, which set cookies. That is ordinary web analytics, and it is disclosed rather than denied. No gameplay data is sent to either. The daily-challenge board stores only a display name, a score, and an optional one-line comment, and only if you submit a run. Full policy: https://margincall.io/privacy ## Links - Website: https://margincall.io - About: https://margincall.io/about - Guides: https://margincall.io/guides - Help: https://margincall.io/help - Contact: https://margincall.io/contact - Extended version of this file: https://margincall.io/llms-full.txt - Twitter/X: https://x.com/margincallgame - itch.io: https://margin-call.itch.io/margincall ## Contact Email: ask@margincall.io ## Version v0.63.0. This file last reviewed 3 September 2026. The authoritative version is `APP_VERSION` in `src/lib/version.ts`, which matches `package.json`. If this file disagrees with that constant, this file is the one that is wrong, and it had drifted eight releases (it claimed v0.43.0) before this review, which is exactly the failure this note was meant to prevent. Update it in the same commit as a version bump.