BOSS

Call Diagonal Spread

Description

Buying a longer-dated call at a lower strike and selling a near-term call at a higher strike, combining a calendar's time-decay edge with a bullish directional tilt.

Setup

  1. Buy one call at a lower strike, a later expiry.
  2. Sell one call at a higher strike, near-term expiry.

Context

Used when a gradual rise is expected, letting the near-term short call fund part of the cost of the longer-dated long call.

Risk Profile

Maximum loss is the net debit paid. Maximum gain depends on both legs' remaining value if the underlying sits at the short strike at the near-term expiry, and is larger than a same-strike calendar thanks to the directional tilt.

Pros

  • Lower cost than an outright longer-dated call.
  • Directional tilt gives it a clearer edge than a flat calendar.
  • Short near-term call generates income against the long position.

Cons

  • More moving parts than a single-expiry spread, harder to price and manage.
  • Needs the move to happen gradually rather than all at once before the near-term expiry.

Effect of Time

Time decay generally helps, since the near-term short call decays faster than the longer-dated long call.

Effect of Volatility

A rise in implied volatility in the back-month option increases the position's value.

Look-Alike Strategies

Live Structure

Live
Index price: $84539.9900
PositionRightRatioStrikeExpiryPremiumFill PriceEst. Fee
Long Call 1 $83500.0000 25 Sep 2026 $1438.1736 $1522.7721 $25.3795
Short Call 1 $85000.0000 24 Sep 2026 $88.7862 $76.1025 $11.0983
Net Cost$1349.3874
Delta0.4714
Gamma-0.0003
Vega8.9244
Theta-143.0946
Rho2.0182
Breakeven(s) $84849.3874

Estimated Cost to Assemble

An estimate of what entering this structure right now would really cost: filling every leg by crossing the spread (the ask when buying, the bid when selling) instead of at the mid-price, plus an estimated exchange fee. Real fees and fills can differ from this estimate.

Mid-Price Cost$1349.3874
Slippage+$97.2822
Execution Cost$1446.6696
Estimated Fees+$36.4778
Total Estimated Cost$1483.1474

Payoff & Greeks vs. Underlying Price

The Greeks curves are a Black-Scholes model using each leg's current implied volatility, holding time to expiry fixed -- not live exchange data at every price, which only exists at the current price (dashed line).

Payoff at Expiration

This structure's value and profit/loss at expiration, at a handful of specific prices: every leg's strike, every breakeven, the current spot, and the chart's own range.

Underlying PriceValue at ExpirationProfit / LossReturn on Cost
$82000.0000 $0.0000 -$1349.3874 -100.0%
$83500.0000 $0.0000 -$1349.3874 -100.0%
$84556.1500 current $1056.1500 -$293.2374 -21.7%
$84849.3874 breakeven $1349.3874 $0.0000 +0.0%
$85000.0000 $1500.0000 $150.6126 +11.2%
$86500.0000 $1500.0000 $150.6126 +11.2%

Delta (model)

Gamma (model)

Vega (model)

Theta (model)

Rho (model)