Get good at 0DTE SPX before it gets expensive.
A 0DTE position lives and dies in one afternoon — and one bad afternoon can erase a month. Learn on days you can rewind, keep only the ideas that survive 900+ sessions of proof, and take a tested edge into today's market instead of a hunch.
100% free · real market data · no real money at risk
- SPX
- —
- Exp. Move
- —
- VIX
- —
A year of screen time in a month of evenings.
Open any past trading day and take the clock: jump ahead, fast-forward the chop, rewind the minute that got away and trade it differently. Every practice day hands you a fresh $100,000 — mistakes here cost exactly nothing.
- Real chains at 1-second resolution — bid/ask, delta, Greeks, IV, exactly as they printed
- "Would that limit order have filled?" — answered instantly
- Replay the same session as many times as it takes
From a hunch to hard evidence in minutes.
Turn "what if I sold the same iron condor every morning?" into a saved strategy in a few clicks — strikes picked the way you actually think about them, exits by rule. And the preview beside the form isn't a sketch: it's a real backtest, streaming in while you build.
- No code, and no naked risk — every structure is defined-risk by construction
- One entry per session keeps every result honest and comparable
- Describe it in plain English and let the assistant write it
Know your worst drawdown before you live it.
No cherry-picked windows, no lucky samples: every strategy is judged on all 900+ sessions, run second by second through the same engine that fills your trades, on $100,000 a day. Same data, same rules for everyone — so any two strategies compare honestly.
- Return, CAGR, Sharpe, Sortino, max drawdown, win rate, profit factor — and the equity curve against SPX buy-and-hold
- Click any day for its orders, decision log, and second-by-second chart
- Every number shown net of your own fees and slippage
Choppy alone. Smoother together.
Blend up to 20 strategies into one book and watch ideas that stumble on different days carry each other. Every member runs a fully funded $100k sleeve, so diversification shows up where it should — a higher Sharpe and a shallower drawdown, never an invented return.
- Combined equity curve, metrics, and P&L calendar for the whole book
- Live preview updates as you pick members
- The clean way to run several entries in one day
Build the reflexes without the account damage.
When research starts feeling easy, graduate to the market's clock: trade today's session tick by tick, wait on real fills, and settle at the 4:00 PM close whether you're ready or not. There's no rewind button here, and the balance carries into tomorrow — a real account in every way except the one that hurts.
- Orders push to you in real time — pending, filled, expired, rejected
- Every settled day stays replayable — scrub back through your fills, moment by moment
- The live SPX chart is public — watch today's tape before you even sign in
A simulator you can't negotiate with.
Fantasy fills teach fantasy lessons, so nothing here flatters you: every order pays a brokerage-grade fee, obeys buying power and margin, fills at the mid with real tick validation, and settles at the close — exercise, assignment, and expiry included. If a number looks good here, it earned it.
- Set your broker's exact rates — every number on the platform recomputes under your costs
- Optional slippage worsens every fill in the market maker's favor
- No fantasy fills, no ignored margin, no free exits
Research runs on your clock. Trading runs on the market's.
One question sorts every screen on the platform: can you rewind the clock? While you can, you're researching — and mistakes are free.
Start with a question
"What if I sold a put spread every morning?" A structure and a rule is enough.
Kill it or keep it
See it across every trading day in minutes. Bad ideas die cheap here.
Trade its worst days
Numbers say whether an edge exists. Practice shows you how it feels to hold.
Take it to the real clock
Paper-trade today's session in real time — same engine, same settlement.
Everything you can click, you can script.
There's no second-class API here: the site itself runs on the same public one you get — accounts, orders, strategies, backtest results, and 1-second market data over HTTP and WebSocket.
- OpenAPI 3 spec at /openapi.yaml
- /llms.txt — the whole platform in one machine-readable index
- Live ticks and session events over WebSocket
# Option-chain snapshot — any second, any day curl "https://api.0dtespx.com/v1/chain?date=2024-11-14&at=13:47" \ -H "Authorization: $TOKEN" # → 1-second bids, asks, and Greeks per strike { "underlying": 6214.83, "expected_move": 34.10, "strikes": [ { "k": 6215, "call_bid": 8.90, "delta": 0.51 } ] }
Bring your AI agent. It already knows the way.
The whole platform is published where agents look for it — so any tool-using agent, from Claude Code to one you built yourself, can read the docs, call the API, and run the research loop for you while you sleep.
- /llms.txt — every doc and endpoint in one agent-readable index
- OpenAPI 3 spec at /openapi.yaml for typed tool definitions
- Simple bearer auth and plain-text errors — trivial for an agent to drive
Read https://www.0dtespx.com/llms.txt to learn the 0DTESPX platform and its API. Then, using my API token, backtest this idea: sell a 16-delta SPX iron condor at 9:35 AM ET with a 50% take-profit, held to the close otherwise. Compare it against 10Δ and 25Δ variants, and report total return, Sharpe, and max drawdown for each — then tell me which one survives.
Questions traders actually ask.
Is it really free?
Yes. Every feature — practice, live paper trading, backtesting, portfolios, market data, and the API — is included with a free account. There's no paid tier and nothing to upgrade to.
Is the market data real?
Yes. Real SPX options market data from every session — quotes, trades, Greeks, and IV at 1-second resolution. Practice and backtests replay exactly what printed.
Do I need a brokerage account?
No. Nothing connects to a broker and no real orders are placed anywhere. It's a research and training environment, not a brokerage.
How realistic are the fills?
Orders fill at the mid with real tick validation, pay a configurable brokerage-grade fee schedule, respect buying power and maintenance margin, and settle automatically at the 4:00 PM ET close. You can add slippage to make it harsher.
Can I automate my research?
Everything on the platform is scriptable over the REST + WebSocket API, with an OpenAPI 3 spec at /openapi.yaml and an AI-readable index at /llms.txt. Bots that run saved strategies live are coming soon.
Can I lose real money here?
No. Balances are simulated and nothing is routed to a market. The whole point is to make your expensive mistakes where they cost nothing. Nothing on the platform is investment advice.
0DTESPX.com is a free paper-trading simulator for education and research. No real orders are placed and no real money is at risk. Nothing here is investment advice.