Diagonal Spread

What you must believe

A directional drift plus time harvesting: you want the calendar's rent engine and a lean in one direction, accepting two expiries and two strikes of complexity.

Construction

The famous version is the poor man's covered call: buy the deep ITM monthly 24,600 CE at about ₹480 (₹400 intrinsic, delta ~0.8) for ₹31,200, and sell the weekly 25,200 CE at ₹55 against it, collecting ₹3,575 per cycle. Index exposure that would otherwise cost ₹16,25,000.

A diagonal's payoff spans two expiries, so a single expiry chart cannot draw it honestly. The calendar chart above this card's cousin (Lesson 25) shows the engine; the deep ITM long adds a steady directional delta on top.

The numbers, before entry

• Max loss: near the ₹31,200 paid for the long leg, if the market collapses and stays down
• Cycle income: up to ₹3,575 per week when the short expires worthless
• Capital: about 2% of owning the equivalent index exposure
• Margin: the long leg covers the short; modest spread margin applies

Greeks profile

Net long delta (~0.55 after the short), long theta from the short leg, mildly long vega from the monthly. A covered call's personality on option-sized capital.

Realistic expectations

Honest print: the long call is a leaky share substitute, it expires too, and pays its own (small) rent. Run well, the weekly sales meaningfully subsidise the long leg's cost across its life. Run badly, both legs decay while the market drifts sideways-down.

Management rules

• Keep the long leg deep ITM, delta 0.75 plus; roll it out a month before its own decay steepens
• Sell short strikes above resistance and the call wall, 0.20 to 0.30 delta
• If assigned risk looms (short deep ITM), roll the short up and out or close the pair

With other strategies

• It replicates the covered call for index traders who cannot hold "NIFTY" in a demat: Lesson 20's strategy at 1/50th of the capital
• It is a calendar plus a vertical fused: pricing it as those two parts catches most mispriced entries
• The wheel's capital-light echo: long leg as the "shares", weekly sales as the rent, without the delivery obligations of stock options
• A put diagonal builds the bearish twin: deep ITM monthly put plus sold weekly puts, for sustained downtrends with income

Common mistakes

• A cheap ATM long leg: time value stacked on time value, both melting
• Selling the short below the long's strike-plus-cost and locking in a structural loss
• Forgetting the long leg's own expiry while collecting weekly rent