Diagonal call spread
A systematic options approach—Diagonal call spread—defined by explicit rules, testable on history, and fragile when costs or regimes change.
Overview
This is a diagonal spread consisting of a long position in a deep ITM call option with a strike price K1 and TTM T′, and a short position in an OTM call option with a strike price K2 and shorter TTM T < T′.
Diagonal call spread sits in the Options chapter of the systematic catalog. On QUSXFI we treat it as a testable hypothesis: specify entries, exits, sizing, and costs—then ask whether edge survives out-of-sample scrutiny.
Discretionary traders often arrive at similar ideas intuitively; the quantitative version forces you to write the rule before you see the next bar. That discipline is what makes results reproducible—or exposes them as luck.
Based on the research catalog 151 Trading Strategies (Kakushadze & Serur, 2018), section 2.20. Educational summary—not a replication of the full formal definition.
Term-Structure Logic
Diagonal call spread trades calendar or diagonal structure—theta and term-structure moves dominate direction in calm tapes.
Map every input Diagonal call spread needs in Options—prices, vol surfaces, fundamentals, or legal milestones—and verify point-in-time integrity.
Implementation and Research Process
For Diagonal call spread, align front and back expiries to your event calendar—macro prints in the front month rewrite term structure.
Decompose Diagonal call spread into signal, portfolio construction, and execution modules—each must be path-independent given the same historical tape.
Log regime tags beside Diagonal call spread performance slices—vol level, rate cycle, liquidity stress.
Risk: What Breaks This Strategy
Diagonal call spread separates calendar risk from direction, but front-month vol shocks can hurt both legs if the term structure inverts violently.
Rolls around events can invert the edge you backtested on smooth historical surfaces.
Theta harvest can look stable until a single name event gaps through both expiries.
Common Mistakes to Avoid
- Deploying Diagonal call spread live before paper trading through at least one adverse Options month.
- Running Diagonal call spread through front-month events without a blackout calendar.
- Confusing Diagonal call spread theta harvest with a vol-neutral free lunch.
- Assuming smooth term structure for Diagonal call spread when macro prints invert the curve.
How to Study This Strategy
- Run a paper book on Diagonal call spread for a full signal cycle; export trades and tag regimes manually.
- Add conservative costs to Diagonal call spread; rerun with 2× spreads and compare drawdown paths.
- Compare Diagonal call spread to one sidebar alternative net of costs—document why you chose this structure.
- List every data field Diagonal call spread needs in Options; verify point-in-time integrity.
- Restate Diagonal call spread (§2.20) as numbered rules another researcher could implement cold.
Key Takeaways
- Diagonal call spread isolates term-structure and theta from raw direction—until front-month events invert the curve you modeled.
- Roll cadence on Diagonal call spread must specify event blackouts; earnings in the front leg rewrite the thesis.
- Calendar spreads lose when front vol explodes faster than back vol catches up.
- Theta harvest on calendars can look stable until one gap through both expiries.
- Compare Diagonal call spread to outright vol trades in the sidebar—time spread is not a free vol-neutral lunch.
Learning Tip
File a dated note after each Diagonal call spread paper session: what worked, what broke, what you will not override next time.
Explore related strategies in the sidebar or return to the full catalog.