After more than 15 years of trading options and running fully automated SPX systems, I can tell you this: most traders don’t lose money because the market moved against them — they lose because they chose the wrong strike prices.
Your strikes determine your probability of profit, your max loss, the credit you receive, and your emotional comfort during the trade. In my Monthly Trend strategy, where I place just one carefully engineered SPX bull put spread per month, the entire edge comes from a disciplined, repeatable strike-selection model.
In this guide, I’ll walk you through exactly how I choose strikes — the same logic behind the Monthly Trend bull put spread signals that have produced strong, steady results for over a decade.
🎧 Listen to the article:
This episode breaks down the full strike-selection framework discussed in the article, including delta zones, support levels, volatility filters, and how these rules are applied inside the Monthly Trend strategy.
Podcast Transcript: Bull Put Spread Strike Selection — Delta, Support & Volatility
Below is the full transcript of the podcast episode, included for accessibility and for traders who prefer reading over listening. This transcript also highlights the systematic strike-selection logic behind the Monthly Trend SPX bull put spread strategy.
1. Understanding Which Strike Matters Most
Many traders focus on premium first, but that often leads to taking unnecessary risk. The short strike is the true engine of the trade, and choosing it correctly determines whether your spread behaves like a high-probability income trade or a lottery ticket. That’s why every professional I’ve worked with starts with strike logic — not expiration, not credit.
A bull put spread consists of two strikes:
- The Short Put — your main risk driver (and the strike that truly matters).
- The Long Put — your insurance to cap max loss.
Your short strike determines:
- The probability of profit.
- How far the index can drop and still keep you safe.
- Your stress level during the trade.
So before we even talk credit or expiration, we need a rule set that consistently selects the safest, highest-probability short strike for the current market.
2. The Delta Framework: How Pros Think About Strikes
If you asked me to pick just one metric to choose bull put spread strikes for the rest of my life, it would be delta.
Delta represents the probability that the option will expire in-the-money. A 0.20 delta put has roughly a 20% chance of expiring in-the-money — which means about an 80% chance of expiring worthless.
2.1 My Delta Rules You Can Use Today
- 0.20 Delta (Safer Zone) — Best for income-focused traders or uncertain markets. Roughly 80% chance of the option expiring worthless, more distance from price, less stress.
- 0.50 Delta (Balanced / Directional) — At-the-money area with a 50/50 outcome. You’re expressing a stronger bullish view and accepting more price risk in exchange for higher credit.
- 0.80 Delta (Aggressive / Tactical) — Deep in-the-money territory for puts, with most of the move already priced in. Premium is large, but risk and emotional pressure are higher. I treat this range as a tactical tool only.
In Monthly Trend, I have a playbook for using the full delta range between 0.20 and 0.80, depending on the market environment:
- In normal conditions, I tend to build income trades around the 0.50–0.60 delta zone to target a clean 1:1 risk-to-reward at entry.
- In high-volatility or more defensive environments, I may step down into the 0.20–0.30 delta region to buy more distance from price.
- In very specific tactical setups (for example, after a fast selloff or in very short-dated structures), I may temporarily move toward the 0.60–0.80 delta region — but always with smaller size, defined risk and a strict exit plan.
2.2 SPX Example (Realistic)
Let’s assume SPX is trading at 6,800:
- 0.20 delta put ≈ 6,700 (further out-of-the-money).
- 0.50 delta put ≈ 6,800 (at-the-money).
- 0.80 delta put ≈ 6,900 (deep in-the-money).
For a core income trade in a quiet bull market, I’m usually interested in something like a mid-delta spread around the 0.50–0.60 region — for example a 6,860/6,850 bull put spread:
- Short put at 6,860 (slightly above the current price, mid-delta).
- Long put at 6,850 (10 points lower to define risk).
That structure often gives me roughly a $5 credit on a $10-wide spread, which is the 1:1 risk-to-reward profile I like at entry. From there, I manage risk with clear delta and price-based exits.
3. Use Support Levels to Reinforce Your Strike Choice
Delta alone gives you probability. Support levels give you structure.
Institutional traders — including the teams I worked with early in my career — always check whether their short strike sits below a meaningful support zone. When price falls, these areas tend to act as natural “speed bumps.”
3.1 How I Identify Support Quickly
- The most recent swing low (10–20 day range).
- Volume shelf (high-volume area on a volume profile).
- Trendline support during an uptrend.
3.2 My Support Rule
If I’m trading lower-delta structures, I always aim to sell the short strike at least 1–2% below the nearest support level. This gives the trade room to breathe — especially important for SPX, which can drop 50–70 points in a single session without breaking trend.
3.3 SPY Example
SPY trades at 500.
Support sits around 493.
A conservative short strike might be 490 (often close to a lower-delta, safer region).
This alignment of delta + support is one reason the Monthly Trend system has had so few losing streaks — only three consecutive losing months since 2013.
4. Adjust Your Strikes Based on Volatility (High IV vs. Low IV)
Volatility changes everything. In fact, it influences strike selection more than most traders realize.
4.1 When IV Is High
- Premiums expand.
- You can sell further out-of-the-money and still earn strong credit.
- In Monthly Trend, I lean into the 0.20–0.30 delta zone when IV is high, using the richer premium to buy more distance from price.
High IV lets you buy a lot of safety — use it.
4.2 When IV Is Low
- Premiums shrink quickly, so far OTM strikes don’t pay enough.
- You’ll usually need to sell somewhat closer to the current price.
- In quiet markets, I may temporarily move closer to the 0.50–0.60 delta region or tighten the spread width to keep the credit meaningful — still with defined risk and controlled sizing.
In rare, very strong bull markets with low IV, I can even consider using tactical structures that touch the 0.60–0.80 delta range inside Monthly Trend — but these are always smaller, short-lived, and managed tightly.
4.3 My Simple IV Rank Rule
- IVR > 50 → choose safer, further OTM strikes (closer to 0.20–0.30 delta).
- IVR < 20 → expect to move somewhat closer to price (potentially 0.50–0.60 delta, with tighter spreads).
5. How Wide Should the Spread Be?
Your long strike determines max loss and influences your credit. Here’s how I think about width:
5.1 Narrow Spread (10–15 SPX points)
- Works well in low-IV environments.
- Reduces max loss per trade.
- Great for smaller accounts.
5.2 Wide Spread (15–30 SPX points)
- Generates more credit.
- Increases maximum loss.
- Better suited to high-IV environments and larger accounts.
6. Full SPX Strike-Selection Example (Real Monthly Trend Logic)
Here’s how I might build a core income trade when SPX trades at 6,800 in a quiet, low-IV bull market:
- Check volatility → IVR 16 (low IV).
- Select delta → choose the 0.60 delta region for a 1:1 risk-to-reward profile.
- Map support → recent support sits in the 6,780–6,800 zone.
- Pick short strike → 6,860 (slightly above current price, around 0.60 delta).
- Pick long strike → 6,850 (10 points lower to define risk).
Final spread: 6,860 / 6,850
Typical credit in this environment: $5.00–$5.15
Probability of profit when managed actively: typically in the 70–80% range.
In other environments, Monthly Trend can shift closer to the mid- or low-delta range for more tactical trades — but always with defined risk and strict exit rules.
These are the types of high-probability spreads we use in the Monthly Trend strategy. If you want to follow the exact trades automatically, you can join the program here:
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7. Quick Strike-Selection Checklist
Before placing any bull put spread, ask yourself:
- Is my short put delta in a sensible range for the current market (for example, 0.50–0.60 for core income trades, 0.20–0.30 when IV is high)?
- Is my short strike aligned with support — or am I trading tactically with a clear plan?
- Is volatility high or low — and did I adjust my strikes accordingly?
- Is the spread width appropriate for my account size and max-loss tolerance?
- Does the credit justify the risk and fit my overall portfolio plan?
- Is the trade structured so I can still sleep at night if price moves against me?
If you check all of these boxes, you’re thinking like a professional options trader.
8. Final Thoughts
Choosing the right strike prices isn’t about guessing market direction — it’s about building smart, repeatable rules that stack probabilities in your favour. That’s exactly how I trade SPX myself, and how I built the system behind Monthly Trend.
In Monthly Trend, I use the full delta playbook — from 0.20 out to 0.80, depending on the market situation, but every trade is still defined-risk, rules-based, and managed with a clear stop so that losing streaks are survivable and the long-term equity curve stays intact.
If you want to access the same monthly SPX bull put spreads I trade — fully automated or delivered by email — you can join us here:
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Your capital deserves a strategy built on discipline, not guesswork. Let’s grow steadily, one smart trade at a time.
By now, you have a complete, rules-based framework for choosing effective bull put spread strikes. These are the same principles I apply in my own SPX trading and inside the Monthly Trend service. To clarify a few recurring questions traders often ask me, here are the most common FAQs.
Frequently Asked Questions About Bull Put Spread Strike Selection
1. What is a safe delta for bull put spread strike selection?
In my own trading, I consider the 0.50–0.60 delta zone the core “sweet spot” for building income trades in quiet bull markets. That’s where you still have a strong probability of the option expiring worthless while collecting meaningful premium. Inside Monthly Trend, I can use the full delta range between 0.20 and 0.80 when the market calls for it — but the higher-delta trades are always tactical, smaller, and managed with tighter exits.
2. How far out-of-the-money should I sell the short put?
As a starting point, I like to place the short put at least 1–3% below the current index price and, ideally, below a clear support level. On SPX, that usually lines up with a lower-delta region such as 0.20–0.30 for defensive, high-probability income trades. When I move closer to the 0.50–0.80 range, it’s typically in low-IV market situations where I’m trading tactically with defined risk and a clear stop.
3. How does volatility change which strikes I should choose?
When implied volatility is high, I can sell strikes further out-of-the-money and still collect a good credit, so I often target safer deltas around 0.20–0.30. When volatility is low and premiums are smaller, I may need to sell somewhat closer to the price, using slightly higher deltas (around 0.50–0.60) and sometimes a narrower spread to keep the risk controlled. In rare cases, I may tap into the 0.60–0.80 range for short-term, tactical structures — but those are not the backbone of the system.
4. How wide should my bull put spread be on SPX or SPY?
The spread width should match your account size and risk tolerance. On SPX, I often use spreads in the range of 15–20 points, which keeps risk defined but still offers a meaningful credit. Smaller accounts may prefer narrower spreads, such as 5–10 points, to keep the maximum loss per trade manageable.
5. What expiration works best for bull put spreads?
For income-focused trades, I find that using options with around 20–40 days to expiration gives a good balance between time decay and flexibility. In my Monthly Trend strategy, I typically place one carefully chosen SPX bull put spread each month and let time decay work in our favour over that period.
6. Is a bull put spread a good strategy for beginners?
Yes, as long as you keep risk defined and position sizes small. A bull put spread has a limited, known maximum loss, which makes it more beginner-friendly than selling naked puts. Where beginners usually struggle is in choosing safe strikes and managing downside risk. That’s exactly why I created the Monthly Trend service — to give newer traders a rules-based way to follow professionally designed trades.
7. How does the Monthly Trend service choose its SPX bull put spread strikes?
In Monthly Trend, I combine three pillars: delta (with a playbook that spans the 0.20–0.80 range), support levels on the S&P 500, and current volatility. In most months, I lean on the safer 0.50–0.60 zone for core income trades, but I’m not afraid to move down the delta ladder and get more tactical when the market gives us a clear edge. I only place one trade per month, typically using about 5% of the account, and I structure the spread so that when we’re right, we aim to earn roughly twice what we risk. You can see the full explanation and performance data here: Monthly Trend SPX Bull Put Spread Signals.
