Paper

Hey Product Hunt! 👋

I've been in the trading industry for over a decade, and I'm still amazed that paper trading platforms don't prepare investors for reality. They give you perfect fills at perfect prices, then you go live and wonder why your strategy isn't working. 🤔

The problem is the "P&L Drift" 📉 - that gap between your paper profits and real losses:

Fantasy platforms show: ✨
- Market orders filled instantly at the mid price ✅
- Limit orders always fill completely ✅
- Stop losses execute perfectly ✅
- $0 fees, $0 slippage 🦄

Reality hits different: 💥
- Market orders slip based on size and liquidity 📊
- Limit orders get partial fills (or miss entirely) ⚠️
- Stop losses gap through your price 🕳️
- SEC/TAF fees, exchange fees, and commissions eat into every trade 💸

I've watched too many traders blow up their accounts because they trained on fantasy fills. They never learned to account for slippage, never sized positions for partial fills, never factored in fees. Their "profitable" strategy was actually a money loser from day one. 😔

That's why we built Paper differently: 🛠️
- Real NBBO matching with queue position
- Volume-aware slippage modeling
- Actual SEC, TAF, and exchange fees
- Market halts, circuit breakers, auction periods
- Realistic latency (not 0ms fantasy land)

Plus, we're the first platform with AI trading support 🤖 - our open-source MCP server lets you trade using natural language with Claude or any AI assistant. Just say "buy 100 shares of Apple" and it works. Perfect for developers building the next generation of AI trading agents.

The broker emulator came from another frustration 🎯 - watching investors sign up with 5 different brokers just to find one that fits their style. Now you can test drive Fidelity's rules, Robinhood's restrictions, or Interactive Brokers' capabilities all in one place. Find your broker before giving them your SSN. 🏦

We show you what trading actually feels like - with all the friction, messiness, and reality that others ignore. Because the worst time to learn about slippage is when it's costing you real money. 💰

Happy to answer any questions about market microstructure, our simulation engine, or why your paper profits might be lying to you!