Credit Spreads for Steady Income
Introduction: Limited Risk Income Selling
While covered calls and cash-secured puts offer excellent income, they require full capital commitment. Credit spreads address this by allowing you to sell premium while limiting capital risk through a protective leg. Two primary varieties exist: bull put spreads and bear call spreads.
Credit spreads are the gateway to more advanced strategies. Understanding their risk/reward profile, optimal IV conditions, and position management will serve you throughout your options trading career.
Bull Put Spread Mechanics
The Basic Structure
A bull put spread is constructed by:
- Sell 1 put at a lower strike (the short put, higher delta)
- Buy 1 put at an even lower strike (the long put, protective)
- Same expiration date for both legs
Real Example: SPY Bull Put Spread
Position:
- Sell 1 SPY April 17 510 put at $1.80 = +$180 credit
- Buy 1 SPY April 17 505 put at $0.70 = -$70 debit
- Net credit received: $110 (the entire profit maximum)
- Width of spread: $5 ($510 - $505)
- Risk: $5.00 - $1.10 = $3.90 per share = $390 max loss
The Three-Part Payoff
| SPY Price at Expiration | Short 510 Put | Long 505 Put | Net P&L |
|---|---|---|---|
| $520 or higher | Expires worthless | Expires worthless | +$110 (max profit) |
| $512.50 | -$0.50 loss | +0 (out of money) | +$60 (partial loss) |
| $507.50 | -$2.50 loss | +$2.50 gain (protect) | -$140 (max loss) |
| $495 or lower | -$15 loss | +$10 gain (protect) | -$390 (max loss) |
The long put at $505 acts as insurance. Once SPY drops below $505, your losses are capped at $390, regardless of how far SPY falls.
Bear Call Spread Mechanics
The Basic Structure
A bear call spread is the inverse of the bull put spread:
- Sell 1 call at a higher strike (the short call, sold against anticipated decline)
- Buy 1 call at an even higher strike (the long call, protective)
- Same expiration date
The bear call spread profits when the stock stays flat or falls. As the stock declines, calls become worthless, and you keep the premium.
Real Example: SPY Bear Call Spread
Position:
- Sell 1 SPY April 17 525 call at $2.10 = +$210 credit
- Buy 1 SPY April 17 530 call at $0.90 = -$90 debit
- Net credit received: $120
- Width: $5 ($530 - $525)
- Max risk: $5.00 - $1.20 = $3.80 per share = $380 max loss
Credit Spread Metrics and Calculations
Maximum Profit Formula
For any credit spread, maximum profit equals the net credit collected:
In our SPY put spread example: Max profit = $110 per contract
Maximum Loss Formula
Maximum loss equals the spread width minus the credit collected:
For the $510/$505 put spread: Max loss = ($5 × 100) - $110 = $390
Risk-to-Reward Ratio
The most important metric for credit spreads:
| Ratio | Implication | Probability of Profit |
|---|---|---|
| 1:1 | Balanced; even odds | ~50% |
| 2:1 | More risk than reward | ~65-70% |
| 1:2 | More reward than risk | ~35-40% |
Our SPY example: $390 loss / $110 profit = 3.5:1 risk/reward. This is aggressive—you need a 78% probability the trade stays profitable. Only use such wide spreads when IV is very high or on index products like SPY with tight bid-ask spreads.
Breakeven Calculation
Bull Put Spread Breakeven
Breakeven = short strike - net credit received
Breakeven = $510 - $1.10 = $508.90
SPY can drop to $508.90 and you break even. Below that, you start losing money. This gives you a ~2.1% cushion from the current $520 price.
Bear Call Spread Breakeven
Breakeven = short strike + net credit received
Breakeven = $525 + $1.20 = $526.20
SPY can rise to $526.20 before you start losing money.
Probability of Profit (PoP)
Understanding PoP
The delta of the short strike approximates the probability that the trade expires in-the-money (and you lose money). Therefore:
If you sell a call with .25 delta, the probability it expires ITM is ~25%, so your PoP is ~75%.
| Short Strike Delta | PoP (approx) | Strategy |
|---|---|---|
| .15 - .25 | 75-85% | Aggressive; wider OTM; lower premium |
| .25 - .35 | 65-75% | Balanced; good PoP and premium |
| .35 - .50 | 50-65% | Conservative; ATM; high premium but closer to ITM |
Professional traders typically target 65-70% PoP, which means selling at .30-.35 delta.
Optimal IV Conditions
Why IV Matters for Spreads
Credit spreads are sold when IV is elevated. High IV means:
- Larger premiums for every strike
- Wider bid-ask spreads (potentially)
- Better risk/reward on the same spread width
Low IV Environment (VIX = 12):
SPY 510/505 put spread: +$0.60 credit
Risk/Reward: $440/$60 = 7.3:1 (terrible!)
High IV Environment (VIX = 28):
Same SPY 510/505 put spread: +$1.40 credit
Risk/Reward: $360/$140 = 2.6:1 (much better)
The Iron Volatility Rule
When VIX > 20, credit spreads offer attractive risk/reward. When VIX < 15, premiums shrink and risk/reward deteriorates. The best credit spread traders enter positions when VIX spikes and exit early (at 50% profit) to lock in gains.
Position Sizing with Credit Spreads
Capital Calculation
Unlike stock purchases, credit spreads use margin. The capital required is the maximum loss, not the maximum profit:
Max loss: $390
Brokers typically require the spread width: $5 × 100 = $500
If you have $10,000 account, you can theoretically do 20 spreads. But good risk management suggests max 1-2% per trade:
1% rule: $10,000 × 1% = $100 max loss per trade
This $390 max loss spread exceeds 1% and shouldn't be done at full size.
The 2% Profit Target
Many professional traders avoid chasing 10%+ monthly returns on credit spreads. Instead, they target 2-3% monthly (24-36% annualized) by:
- Selling at 65-70% PoP (not 80%+)
- Closing at 50% max profit (not waiting to expiration)
- Exiting early on volatility spikes
- Never averaging down on losing trades
Managing Credit Spreads
The 50% Rule
Why? Because closing early locks in gains, frees capital, and lets you redeploy into better opportunities. Waiting to expiration risks whipsaws and doesn't significantly improve your return.
SPY bull put spread: collect $110 credit
3 days later, SPY rallies; spread is now worth $60
Profit if you close: $110 - $60 = $50 (45% of max)
Annualized return: $50 / $390 max loss × (365/3 days) = 152% annualized!
Compare to holding to expiration (41 days) for $110 profit = $110/$390 × (365/41) = 103% annualized. Better to take the 50% quickly and move on.
Exit Rules for Losers
When a credit spread goes against you, have a plan:
| Loss Level | Action | Rationale |
|---|---|---|
| -25% of max loss | Add to losers (optional) | Collect more premium to average down |
| -50% of max loss | Halt new orders; assess | Trade is deteriorating; reassess thesis |
| -75% of max loss | Close the trade | Preserve capital; don't let winner-take-all losses happen |
| -100% of max loss | Already exited or reassign | Should never reach this on spreads with protective legs |
Real Monthly Example: SPY Iron Condor (Two Spreads Combined)
Bull Put Spread (bottom half):
Sell 510 put / Buy 505 put: +$110 credit
Breakeven: $508.90
Bear Call Spread (top half):
Sell 530 call / Buy 535 call: +$120 credit
Breakeven: $531.20
Combined Condor:
Total credit: $230
Max profit: $230
Max loss: $770 (if stock pierces a wing)
Profit zone: $508.90 - $531.20
Scenario 1 - 10 Days Out, SPY at $520:
Both spreads OTM, position up $115 (50% profit target hit)
Close both sides; collect $115 profit
Return: $115 / $770 max loss = 15% annualized over 41 days = 134% annualized
Key Takeaways
2. Bull put spreads profit when stocks stay flat or rise; bear call spreads profit when stocks stay flat or fall.
3. Sell when IV is high: Premiums expand, risk/reward improves dramatically.
4. Target 65-70% PoP: This means selling at .30-.35 delta, balancing premium and safety.
5. Close winners at 50% profit: Lock in gains and redeploy capital faster than holding to expiration.
6. Realistic returns: 1-3% per month on capital at risk is excellent; don't chase 5-10% per trade.