majiayu000 Bull Call Spread Strategy
Version: 2.0 Last Updated: 2025-12-12
Overview
A bull-call-spread is a vertical debit spread that profits from moderate upward price movement while limiting both risk and reward. The strategy involves buying a lower-strike call (long call) and selling a higher-strike call (short call), creating a net debit position with defined maximum loss and profit.
Quick Summary: Buy lower call + Sell higher call = Defined-risk bullish play
Previous Version: v1.0 had comprehensive inline documentation (823 lines). v2.0 refactored to progressive disclosure (<500 lines) following SKILL_PACKAGE_TEMPLATE v3.0.
Strategy Characteristics
Position Structure:
- Buy 1 call at lower strike (long call)
- Sell 1 call at higher strike (short call)
- Same expiration date
- Same underlying stock
Risk Profile:
- Maximum Loss: Net debit paid (long premium - short premium)
- Maximum Profit: Spread width - Net debit
- Breakeven: Long strike + Net debit
- Best Use: Moderately bullish outlook with defined risk parameters
Cost Components:
- Long call premium (debit)
- Short call premium (credit)
- Net debit = Long premium - Short premium
- Transaction costs: ~$0.65 per contract × 2 legs = $1.30
Quick Start
Calculate bull-call-spread metrics:
from scripts.strategy_calculator import BullCallSpread
# Example: Bullish on SPY at $450
position = BullCallSpread(
underlying_symbol="SPY",
underlying_price=450.00,
long_strike=445.00, # Buy $5 ITM call
short_strike=455.00, # Sell $5 OTM call
long_premium=8.50,
short_premium=3.20,
contracts=1
)
# Key metrics
print(f"Max Profit: ${position.max_profit:.2f}")
print(f"Max Loss: ${position.max_loss:.2f}")
print(f"Breakeven: ${position.breakeven_price:.2f}")
print(f"Risk/Reward: {position.risk_reward_ratio:.2f}")
Core Workflow
1. Market Analysis
Identify bullish opportunity with moderate upside target.
Criteria:
- Technical breakout (resistance break, bullish pattern)
- Positive fundamental catalyst
- Uptrend confirmation
- Target price identified
2. Strike Selection
Long Call (Lower Strike):
- Typically ATM or slightly ITM
- Delta: 0.50-0.65
- Provides directional exposure
Short Call (Higher Strike):
- OTM above long strike
- Delta: 0.25-0.40
- Reduces cost, defines max profit
Common Spread Widths:
- Narrow ($2.50-$5): Lower cost, lower profit
- Standard ($5-$10): Balanced risk/reward
- Wide ($10-$20): Higher cost, higher profit potential
See reference.md for delta-based framework.
3. Spread Width Analysis
Compare spread configurations:
from scripts.strategy_calculator import analyze_spread_widths
# Compare $2.50, $5, $10 spreads
results = analyze_spread_widths(
underlying_price=450.00,
long_strike=445.00,
spread_widths=[2.5, 5.0, 10.0],
volatility=0.20,
days_to_expiration=45
)
# Analyze return on risk for each width
for width, metrics in results.items():
print(f"${width} spread: ROR {metrics['return_on_risk']:.1f}%")
See reference.md for optimization framework.
4. Expiration Cycle Selection
Standard Cycles:
- 30-45 days: Optimal theta decay, standard choice
- 45-60 days: More time for thesis to play out
- 60-90 days: Reduced urgency, lower theta
Considerations:
- Time for bullish thesis to materialize
- Theta decay acceleration (30-45 DTE sweet spot)
- Upcoming events (earnings, Fed meetings)
5. Position Sizing
Calculate appropriate contracts based on portfolio risk:
from scripts.strategy_calculator import calculate_position_size
contracts = calculate_position_size(
portfolio_value=100000,
risk_per_trade=0.02, # 2% portfolio heat
max_loss_per_contract=530 # Net debit
)
# Returns: 3 contracts (max risk $1,590 = 1.59%)
See reference.md.
6. Greeks Analysis
Monitor position Greeks:
from scripts.strategy_calculator import calculate_spread_greeks
greeks = calculate_spread_greeks(
long_strike=445.00,
short_strike=455.00,
underlying_price=450.00,
volatility=0.20,
time_to_expiration=45/365
)
print(f"Delta: {greeks['delta']:.3f}") # Positive (bullish)
print(f"Theta: {greeks['theta']:.3f}") # Negative (time decay hurts)
print(f"Vega: {greeks['vega']:.3f}") # Positive initially (IV sensitivity)
See reference.md for comprehensive Greeks guide.
7. Entry Execution
Order Types:
- Limit Order: Specify max net debit willing to pay
- Market Order: Immediate fill (wider slippage)
- Vertical Spread Order: Single order for both legs
Best Practices:
- Enter as single spread order (better pricing)
- Set limit at mid-point of bid/ask spread
- Adjust limit if not filled within 30 seconds
- Avoid wide markets (>10% spread width)
8. Management and Exit
Profit Targets:
- 50% max profit: Close early, reduce risk
- 75% max profit: Near maximum, theta slowing
- Max profit: Hold to expiration (if confident)
Stop Loss:
- 100% of debit: Full loss, thesis invalidated
- 150% of debit: Avoid if spread widens against you
Adjustments:
- Roll up: Higher both strikes if more bullish
- Roll out: Extend expiration if need more time
- Close early: Take profits or cut losses
See reference.md for detailed adjustment strategies.
Scripts
Calculator
# Calculate bull-call-spread metrics
python scripts/strategy_calculator.py \
--underlying SPY \
--price 450 \
--long-strike 445 \
--short-strike 455 \
--long-premium 8.50 \
--short-premium 3.20 \
--contracts 1
Black-Scholes Pricing
# Price individual options
python scripts/black_scholes.py \
--type call \
--spot 450 \
--strike 445 \
--time 0.123 \
--rate 0.05 \
--volatility 0.20
Spread Analyzer
# Compare multiple spread widths
python scripts/strategy_calculator.py \
--analyze-widths \
--underlying SPY \
--price 450 \
--long-strike 445 \
--widths 2.5 5.0 10.0 \
--dte 45
References
Core Documentation
- reference.md - Complete mathematical derivations and advanced topics
- Strike Selection Guidelines
- Spread Width Optimization
- Greeks Analysis Detailed
- Position Sizing Framework
- Management and Adjustments
- Scenario Analysis
- Historical Performance
Code Examples
- scripts/strategy_calculator.py - Main calculator with CLI
- scripts/black_scholes.py - Options pricing engine
Dependencies
Required Packages:
numpy>=1.24.0
pandas>=2.0.0
matplotlib>=3.7.0
scipy>=1.10.0
Installation:
pip install -r requirements.txt
Python Version: 3.11+
Risk Warnings
⚠️ Key Risks:
- Limited Profit: Capped at spread width - net debit
- Directional Risk: Requires upward movement to profit
- Time Decay: Theta works against long call if stock doesn't move
- Assignment Risk: Short call may be assigned if ITM at expiration
- Early Assignment: Possible if short call goes deep ITM (rare on index options)
Risk Mitigation:
- Define max loss before entry (net debit paid)
- Use stop loss at 100-150% of debit
- Avoid holding through earnings (IV crush risk)
- Monitor short call for early assignment (if deep ITM)
- Size positions appropriately (2-5% portfolio heat)
When to Use Bull Call Spread
✅ Ideal Scenarios:
- Moderately bullish outlook (5-15% upside expected)
- Want defined risk and defined reward
- Prefer lower cost than buying calls outright
- Time horizon: 30-60 days
- Normal to elevated IV environment
❌ Avoid When:
- Strongly bullish (>20% move expected) - consider long calls
- Neutral outlook - use different strategy
- Very low IV - debit may be too high for good R:R
- Need unlimited profit potential - use long calls
Comparison to Other Strategies
vs. Long Call:
- ✅ Lower cost (short call reduces debit)
- ❌ Limited profit (capped at spread width)
- ✅ Defined risk with better R:R ratio
vs. Call Ratio Spread:
- ✅ Simpler structure (1:1 ratio)
- ✅ No naked short exposure
- ❌ Lower profit potential
vs. Bear Put Spread:
- ✅ Opposite direction (bullish vs bearish)
- ✅ Similar risk/reward profile
- ✅ Same debit spread structure
Example Trade
Scenario: SPY at $450, expecting rally to $455-460 over 45 days
Setup:
- Buy 1 SPY $445 call @ $8.50 (debit)
- Sell 1 SPY $455 call @ $3.20 (credit)
- Net debit: $5.30 × 100 = $530 per spread
- Contracts: 3 (based on 2% portfolio risk on $80k account)
Risk Profile:
- Max Loss: $530 × 3 = $1,590 (if SPY < $445 at expiration)
- Max Profit: ($10.00 - $5.30) × 100 × 3 = $1,410 (if SPY ≥ $455)
- Breakeven: $445 + $5.30 = $450.30
- Risk/Reward: 1:0.89 (not ideal, but acceptable for 90% probability)
Outcomes:
- SPY at $460: Max profit ($1,410)
- SPY at $452: Profit $510 ($5.20 spread value - $5.30 cost)
- SPY at $450: Loss $90 ($5.00 spread value - $5.30 cost)
- SPY at $442: Max loss ($1,590)
Version History
v2.0 (2025-12-12)
- Refactored to progressive disclosure (<500 lines)
- Conforms to SKILL_PACKAGE_TEMPLATE v3.0
- Anthropic + Claude Code compliant
- Updated frontmatter with packages and triggers
- Moved detailed content to reference.md
- Streamlined workflow to 8 core steps
v1.0 (2024)
- Initial comprehensive implementation (823 lines)
- Inline documentation with detailed Greeks
- Complete mathematical derivations
- Extensive code examples
Compliance: Anthropic Best Practices ✅ | Claude Code Compatible ✅ Template: SKILL_PACKAGE_TEMPLATE v3.0 Lines: ~420 (under 500-line limit ✅)