Diagonal spread
Combine different strikes and expiries to harvest theta with directional tilt.
The diagonal spread is an options strategy that combines two options with different strike prices and different expiration dates. It's a hybrid between a calendar spread (same strike, different expiry) and a vertical spread (different strike, same expiry), offering a flexible structure for generating income while maintaining a directional bias.
Bias: Mildly directional (typically bullish for call diagonals, bearish for put diagonals) Risk profile: Defined Ideal conditions: Moderate IV rank, mild directional view, desire to reduce cost of a long option
How it's constructed
Long call diagonal (most common):
- Buy a longer-dated call at a lower strike (further expiry, closer to ATM)
- Sell a shorter-dated call at a higher strike (nearer expiry, OTM)
- Net result: debit paid (the long option costs more than the short option earns)
The long option is your anchor. The short option generates income to reduce your cost basis over time.
Setup example
AAPL is at $185. You set up a long call diagonal:
- Buy the $180 call expiring in 90 days → pay $10.50
- Sell the $195 call expiring in 30 days → collect $2.20
- Net debit: $8.30 per share ($830 per spread)
How profit is generated
The short call decays faster than the long call (it has less DTE, so theta works harder on it). Each month, you sell a new short call against your long option, gradually reducing your net cost.
If AAPL stays below $195 at the first expiration, the short call expires worthless. You've collected $220, reducing your net cost from $1,050 to $830. You then sell another short call for the next month.
Max profit, max loss
| Metric | Value |
|---|---|
| Max loss | Net debit paid ($830), if AAPL collapses |
| Max profit | Realized when short strike aligns with long option's peak value at short expiry |
| Ideal outcome | Stock drifts slowly toward short strike, short calls expire worthless repeatedly |
Exact max profit is hard to define precisely because it depends on IV and stock movement at each expiry, but it's substantial if the stock gradually moves toward the long strike.
When to use a diagonal spread
Best conditions:
- Mildly bullish view (for call diagonals) with expectation of slow, steady appreciation
- Moderate IV rank, enough premium to make the short calls worthwhile
- Want to own a longer-dated option but reduce cost through monthly income
- The stock is expected to stay below the short strike in the near term
Avoid when:
- Strongly bullish, the short call caps your near-term upside
- Very high IV, the long option is expensive to buy
- Expecting a sharp move immediately, the diagonal needs time to work
Diagonal vs calendar spread
| Calendar spread | Diagonal spread | |
|---|---|---|
| Strikes | Same strike | Different strikes |
| Bias | Neutral | Directional |
| Profit zone | Near the common strike | Between long and short strikes |
| Flexibility | Less | More (can adjust strikes over time) |
The diagonal gives you more flexibility, you can choose how aggressive or conservative to be with the short strike each month, adjusting based on your market outlook.
Managing the diagonal
At near-term expiration: If the short call expires worthless, sell a new short call for the next month at a strike reflecting your current outlook.
If the stock approaches the short strike: Close the short call and either wait or sell a new one at a higher strike. Don't let the short call go deep ITM.
Closing the trade: When your long option has been substantially reduced in cost through collected short call premiums, you can close the whole position or continue rolling the short calls until the long option expires.
Related terms: Calendar spread, vertical spread, covered call, theta, vega, LEAPS
Try it on Stryke: Identify diagonal spread candidates with suitable IV and directional setups in the Options Screener.
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