What causes the bull-call spread's upside cap?
Reveal the worked answer
The higher-strike short call.
The sold option finances part of the cost and offsets later upside.
Advanced Options · ADV-01 · Core
Think in risk shapes
What exposure does the combination actually create?
What you will learn and prerequisites
- Explain the mechanism in the lesson question.
- Reproduce the worked comparison and recognize its failure case.
Read first: Read a contract and its premium, Rights, obligations and expiration, Defined payoff risk is not margin, Read the whole multi-leg ticket
Advanced options begins with decomposing risk, not memorizing more names. A combination can be directional, convex, range-focused or relative-value, and its current sensitivities can change with spot, time and IV.
A strategy nickname is a starting description, not a complete specification.
Understand the mechanism
A long vanilla option has positive Gamma and Vega in smooth European BSM, but its Theta is not universally negative in every state. Short quantities reverse sensitivities. Multi-leg positions can change their net Greek signs across states.
Terminal payoff and pre-expiry value are distinct. A calendar cannot be reduced to a single fixed terminal V by pretending both legs expire together.
Walk through the process
Read every signed leg and the cash flow. Identify dominant risks now and in adverse states. Test flat spot with time passing, a directional jump and an IV-surface change.
Progress means explaining why a chosen exposure fits the thesis, not increasing complexity or leverage.
Model and implementation boundary
These are complete fictional reading examples, not live opportunities. Terminal identities assume the stated common settlement. Multi-expiry values require a surviving-leg model. Costs, assignment and financing can alter realized outcomes; a mathematical bound alone does not guarantee the same operational loss path.
A worked example
A fictional 100/105 bull-call vertical pays two points. Its terminal P/L is −200 below 100, rises through zero at 102 and caps at +300 above 105 for one standard spread.
The short call is what limits participation above 105. Removing it does not 'improve' the same trade for free: it changes cost and risk. The graph shows the full combination rather than one leg alone.
Think in risk shapes—worked comparison
Vertical: Vertical terminal P/L (USD)
Horizontal: Underlying at common expiry (USD)
1. Fictional example
Read the graph as a data table
| Underlying at common expiry (USD) | Fictional example |
|---|---|
| 90 | -200 |
| 91 | -200 |
| 92 | -200 |
| 93 | -200 |
| 94 | -200 |
| 95 | -200 |
| 96 | -200 |
| 97 | -200 |
| 98 | -200 |
| 99 | -200 |
| 100 | -200 |
| 101 | -100 |
| 102 | 0 |
| 103 | 100 |
| 104 | 200 |
| 105 | 300 |
| 106 | 300 |
| 107 | 300 |
| 108 | 300 |
| 109 | 300 |
| 110 | 300 |
| 111 | 300 |
| 112 | 300 |
| 113 | 300 |
| 114 | 300 |
| 115 | 300 |
What would invalidate the reading?
A trader assigns fixed Greeks to a strategy by name or treats a cheaper structure as automatically better. Its risk shape can differ fundamentally.
Check your understanding
Try the question before revealing its answer. These are reading checks, not trading certification or a site completion record.
What is the critical failure to avoid?
Reveal the worked answer
A trader assigns fixed Greeks to a strategy by name or treats a cheaper structure as automatically better. Its risk shape can differ fundamentally.
Explain this risk before treating the example as a decision rule. A correct calculation does not guarantee a favorable market outcome.
Return to the question: What exposure does the combination actually create? State the observed facts, the assumptions and the failure condition separately.
Sources, assumptions and downloadable script
External references support definitions and conventions. Worked scenarios and prose are original. No current quotes or dealer inventory are claimed.
Read this lesson as Markdown · Download its JavaScript content module