No. Quotes come from CBOE public delayed quotes, delayed about 15 minutes; a chain older than about 30 minutes counts as stale and the page blocks new opens — never replaced with made-up quotes.
No. The fallback source (Yahoo ^GSPC) only supplements the spot price, never the options chain; the chain comes only from CBOE.
$0.65 per contract per side, all P&L net of fees; the fee circuit breaker trips at $60 per day.
No. This simulator uses a simplified convention: strike × 20% × 100 × contracts, released on close. Under it, selling 1 high-strike SPX contract can exceed the $100,000 starting cash — that is a limitation of the simplified convention, shown as-is.
If there is no valid same-day chain, the page shows the next trading day’s expiry and labels it as not 0DTE, never presenting an old chain as today’s chain; if data is stale, new opens stay disabled.
No. No account, no password, no cookie-based login; the paper account lives only in the browser’s localStorage and can be reset with one click.
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