name: options-payoff
description: >
Render an interactive options payoff chart — expiry P&L plus Black-Scholes theoretical
value — with sliders for strikes, premium, IV, DTE, and spot. Use this skill whenever
the user describes or shares an options position or strategy and wants to see how it
makes or loses money: vertical, calendar, diagonal, or ratio spreads, butterflies,
condors and iron condors, straddles, strangles, covered calls, protective or naked
puts, or any multi-leg structure. This includes pasted strikes, premiums, and
expiries, requests like "show me the payoff" or "draw the P&L curve", and broker
screenshots (IBKR, TastyTrade, Robinhood). Use it even when details are partial —
defaults fill the gaps.
Options Payoff Curve Skill
Generates a fully interactive HTML widget (via visualize:show_widget) showing:
Expiry payoff curve (dashed gray line) — intrinsic value at expiration
Theoretical value curve (solid colored line) — Black-Scholes price at current DTE/IV
Dynamic sliders for all key parameters
Real-time stats: max profit, max loss, breakevens, current P&L at spot
Step 1: Extract Strategy From User Input
When the user provides a screenshot or text, extract:
Field
Where to find it
Default if missing
Strategy type
Title bar / leg description
"custom"
Underlying
Ticker symbol
SPX
Strike(s)
K1, K2, K3... in title or leg table
nearest round number
Premium paid/received
Filled price or avg price
5.00
Quantity
Position size
1
Multiplier
100 for equity options, 100 for SPX
100
Expiry
Date in title
30 DTE
Spot price
Current underlying price shown in the screenshot or text
live quote (see below); middle strike only if no quote is available
IV
Shown in greeks panel, or estimate from vega
20%
Risk-free rate
—
4.3%
Spot for screenshots: spot is the underlying's current price, and broker screenshots often omit it or show it far from the strikes — don't read it off the strike labels. Use the price shown, else a live quote (the SPX probe below, or yfinance for other underlyings). Fall back to the middle strike only when no quote is available, and tell the user you did.
For expiry curve of calendar: near leg expires worthless, far leg = BS with remaining T.
Iron Condor Payoff (expiry)
put_spread = max(K2-S, 0) - max(K1-S, 0) // short put spread
call_spread = max(S-K3, 0) - max(S-K4, 0) // short call spread
payoff = credit_received - put_spread - call_spread
Step 4: Render the Widget
Use visualize:read_me with modules ["chart", "interactive"] before building.
Required Controls (sliders)
Structure section:
All strike prices (K1, K2, K3... as needed by strategy)
Premium paid/received
Quantity
Multiplier (100 default, show for clarity)
Pricing variables section:
IV % (5–80%, step 0.5)
DTE — days to expiry (0–90)
Risk-free rate % (0–8%)
Spot price:
Full-width slider, range = [min_strike - 20%, max_strike + 20%], defaulting to ACTUAL current spot
Required Stats Cards (live-updating)
Max profit (expiry)
Max loss (expiry)
Breakeven(s) — show both for two-sided strategies
Current theoretical P&L at spot
Chart Specs
X-axis: SPX/underlying price
Y-axis: Total USD P&L (not per-share)
Blue solid line = theoretical value at current DTE/IV
Gray dashed line = expiry payoff
Green dashed vertical = strike prices (K2 center strike brighter)
Amber dashed vertical = current spot price
Fill above zero = green 10% opacity; below zero = red 10% opacity
Tooltip: show both curves on hover
Code template
Use this JS structure inside the widget, adapting pnlExpiry() and bfTheory() per strategy:
// Black-Scholes helpers (always include)
function normCDF(x) { /* Horner approximation */ }
function bsCall(S,K,T,r,sig) { /* standard BS call */ }
function bsPut(S,K,T,r,sig) { /* standard BS put */ }
// Strategy-specific expiry payoff (returns per-share value BEFORE premium)
function expiryValue(S, ...strikes) { ... }
// Strategy-specific theoretical value using BS
function theoreticalValue(S, ...strikes, T, r, iv) { ... }
// Main update() reads all sliders, computes arrays, destroys+recreates Chart.js instance
function update() { ... }
// Attach listeners
['k1','k2',...,'iv','dte','rate','spot'].forEach(id => {
document.getElementById(id).addEventListener('input', update);
});
update();
Step 5: Respond to User
After rendering the widget, briefly explain:
What strategy was detected and how legs were mapped
Max profit / max loss at current settings
One key insight (e.g., "spot is currently 950 pts below the profit zone, expiring tomorrow")
Keep it concise — the chart speaks for itself.
Reference Files
references/strategies.md — Detailed payoff formulas and edge cases for each strategy type
references/bs_code.md — Copy-paste ready Black-Scholes JS implementation with normCDF
Read the relevant reference file if you're unsure about payoff formula edge cases for a given strategy.
How do I install options-payoff?
Download plugins/market-analysis/skills/options-payoff/SKILL.md from the publisher, or copy the path and open the repository. PlugMCP lists the skill and does not host the file.
Where does options-payoff live?
The publisher keeps it at https://github.com/himself65/finance-skills.
Which agents can use options-payoff?
Claude, Cursor, and Codex can read a SKILL.md you add from the publisher's repository.