Double Calendar
A put calendar combined with a call calendar at two different strikes, profiting from theta and from a rise in volatility while price stays in a range.
Profit / Loss Diagram
Double Calendar at the short expiration
What is this strategy?
The Double Calendar combines two simultaneous calendar spreads around the current price: a put calendar at a strike below the underlying and a call calendar at a strike above. In each calendar you sell the near-dated option and buy the longer-dated one at that same strike, so the position is a net debit that gains value as the short options decay faster than the longs. It is, in essence, the calendar version of the Iron Condor: a wide profitable range with two profit peaks around the chosen strikes.
Unlike the Double Diagonal — where each leg uses different strikes — in the Double Calendar the two options on each side share a strike and differ only in expiration. That gives it a clearly vega-positive profile: since the longer-dated options carry more vega than the shorts, the position benefits when implied volatility rises and suffers when it falls (IV crush). Its profit engine is twofold: the passage of time (positive theta) on the short legs, and a volatility expansion on the long legs.
It is a neutral strategy, ideal for low implied volatility environments expected to rise, with price moving little and finishing between the two strikes when the short options expire. It requires moderate capital and active management near the short expiration. It offers a wider profitable range than a single calendar, but it is more sensitive to sharp moves in the underlying and to falls in volatility.
Construction
| Action | Instrument | Strike | Expiration | Example |
|---|---|---|---|---|
| SELL | 1 Put (short) | OTM (below) | 30 DTE | -1 SPY Mar 420 Put |
| BUY | 1 Put (long) | Same strike | 60 DTE | +1 SPY Jun 420 Put |
| SELL | 1 Call (short) | OTM (above) | 30 DTE | -1 SPY Mar 430 Call |
| BUY | 1 Call (long) | Same strike | 60 DTE | +1 SPY Jun 430 Call |
Example
Scenario: SPY at $425 with low implied volatility you expect to rise. You are looking to profit from theta and from a volatility expansion while price stays between 420 and 430.
- Put Sold (March) -1 SPY Mar 420 Put @ $2.50
- Put Purchased (June) +1 SPY Jun 420 Put @ $4.00
- Call Sold (March) -1 SPY Mar 430 Call @ $2.30
- Call Purchased (June) +1 SPY Jun 430 Call @ $3.80
- Total Net Debit $300 ((4.00−2.50) + (3.80−2.30) × 100)
- Maximum Gain Near the strikes at the short expiration (variable)
- Maximum Loss $300 (net debit paid)
- Optimal Zone Price between $420 and $430 at the March expiration
The Greeks
The deltas of the call and put calendars offset around the current price. Small moves barely affect P&L.
The two short legs decay faster than the longs. The passage of time adds value while price stays in range.
The longer-dated options dominate net vega. A rise in implied volatility benefits the position; a fall (IV crush) hurts it.
Short gamma dominates near the short expiration. Large fast moves in the underlying produce losses.
Position Management
- 01 Match the Strikes to the Expected Range Place the put and call strikes at the edges of the range where you think price will move. The wider apart, the wider the profitable range but the smaller the maximum gain.
- 02 Watch Both Short Legs Near the short expiration, close whichever short leg is winning and let the one still out of the money expire. Manage each calendar independently.
- 03 Roll the Shorts to Extend If the thesis still holds, roll the short options to the next expiration cycle to keep collecting theta against the longs you still hold.
- 04 Take Profits at 50% Do not chase the theoretical maximum. If you reach 50–75% of the potential gain, close the whole position to bank the result.
- 05 Define Movement Limits Set a stop if price drifts too far from the strikes or if implied volatility collapses. Both scenarios erode the theta advantage.