Put-Call Parity Scanner

Detect options mispricing by analyzing put-call parity violations.

Screener results are algorithmic and for informational purposes only. Scores do not constitute trading recommendations. Past performance is not indicative of future results. See Terms §17.

Scan Parameters
Violations Found

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Underlying Price

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Risk-Free Rate

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Dividend Yield

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Contracts Scanned

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Parity Violations
Strategy Strike Expiry DTE Call Bid Call Ask Put Bid Put Ask Theoretical Actual Violation $ Profit $ Ann. Return Min OI
Enter a symbol and click "Scan" to check for parity violations
Important Disclaimer

Put-call parity applies exactly only to European-style options. Most US equity options are American-style, meaning early exercise premium and upcoming dividends can cause natural deviations from theoretical parity. Market makers typically eliminate true arbitrage within milliseconds. Violations shown here are primarily educational — they illustrate market efficiency and structural pricing factors rather than executable risk-free profits.

Put-Call Parity Explained

The Formula

Put-Call Parity states: C - P = S - K × e-rT

Where C = call price, P = put price, S = stock price, K = strike price, r = risk-free rate, T = time to expiration in years.

How It Works

  • Theoretical Diff: The value that C - P should equal according to the parity formula.
  • Actual Diff: What C - P actually equals using market bid/ask prices.
  • Violation: The gap between theoretical and actual. Larger gaps suggest greater mispricing.
  • Long Synthetic: Buy call + sell put. Profitable when the synthetic is cheaper than theoretical.
  • Short Synthetic: Sell call + buy put. Profitable when the synthetic is richer than theoretical.

Why Violations Occur

  • American-style options allow early exercise, adding a premium not captured in the European parity formula
  • Upcoming dividends affect put-call parity — the stock drops by the dividend amount on ex-date
  • Wide bid-ask spreads on illiquid options create apparent violations that vanish at execution
  • Interest rate assumptions — the scanner uses the Fed Funds Target Upper rate, but actual borrowing costs vary