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BlogPublished May 30, 2026 · 18 min read

Position Sizing and Max Collateral Rules for Option Sellers

Illustration of a pie chart for position sizing and collateral allocation
Contract count is vanity; pledged collateral as % of net liquidating value is the budget.

Position sizing for option sellers: max collateral as % of NLV, per-ticker caps, sector limits, and five rules to size cash-secured puts and spreads without over-pledging.

Position sizing for option sellers is not picking the highest premium on the chain. It is deciding how much of your account can be stock after a bad month—and writing that number down before temptation arrives.

Brokers show buying power; disciplined sellers track pledged collateral against net liquidating value (NLV), cap single-name exposure, and leave cash unpledged for rolls and assignment.

This guide gives practical max-collateral rules, formulas for cash-secured puts and spreads, and how to log sizing decisions in a journal.

You will learn portfolio-level collateral caps, per-underlying limits, five sizing rules, and links to puts, collateral, and earnings guides on this blog.

Why position sizing is collateral sizing

A cash-secured put pledges strike × 100 per contract. A put credit spread pledges margin per broker rules. Until those obligations close, that capital is not available for new trades or emergencies.

Options collateral and buying power explains cash-secured vs. margin; this article sets how much of the book can be pledged at once.

Rule 1: Max collateral as % of NLV

Many disciplined sellers cap total pledged collateral between 30% and 60% of NLV—exact % is personal and depends on income needs, other assets, and sleep quality. The point is a written ceiling, not the highest number the broker allows.

Example framework (illustrative, not advice):

  • Conservative: 30–40% max collateral / NLV
  • Moderate: 40–50%
  • Aggressive: 50–60%—little buffer for gaps or stacked assignment
  • Above 60%: one bad week can force closes at the worst prices

The FINRA and SEC emphasize that options can involve substantial risk—headline buying power ignores correlation and gaps.

Rule 2: Per-underlying and per-sector caps

Even with portfolio collateral under your max, three lines on one ticker can assign into an oversized stock position. Cap contracts per underlying (e.g. 1–3 for retail) and per sector (e.g. tech ≤ 25% of pledged collateral).

Market chart illustrating concentration risk for option sellers
Sector caps matter when macro moves hit every name in the group at once.

Rule 3: Size one trade for assignment, not for premium

Before adding a contract, ask:

  1. If assigned on this strike, will I hold 100 shares comfortably?
  2. If assigned on all open puts in this name, am I still within per-ticker cap?
  3. Does collateral after this trade stay under max % NLV?
  4. Is there cash left to roll or hedge if price drops 10%?
  5. Did I log strike, premium, collateral, and rule checks?

Selling puts: discipline and capital is the strategy deep dive.

Spreads vs. naked puts: sizing differences

Defined-risk spreads vs. cash-secured puts:

  • Put credit spread — max loss ≈ width minus credit; size by max loss, not short strike cash
  • Cash-secured put — collateral = strike × 100; size by stock you are willing to own
  • Covered call — 100 shares per contract; size by equity book, not option premium

Credit spreads vs. naked puts compares structures.

Rule 4 and 5: Calendar and review cadence

Stagger expirations so one Friday cannot assign your entire book. Review collateral / NLV weekly and after large market moves—not only when premium looks generous.

Pair rules with options trading journal metrics and earnings by account size for realistic income expectations.

Reviewing trade records for collateral and position sizing
Written caps only work if you measure pledged collateral against them every week.

Conclusion: size the book, then the contract

Key takeaways:

  • Set max collateral % of NLV in writing
  • Cap per ticker and per sector
  • Size for assignment and correlation, not premium alone
  • Log and review weekly

Educational only—not personal financial advice. Explore Option Journal or the blog index.

Frequently asked questions

What is position sizing for option sellers?

Position sizing is how much collateral and risk you allocate per trade and across the book—usually expressed as a percent of net liquidating value and caps per ticker or sector.

What percent of my account should be in collateral?

Many disciplined sellers cap cash-secured put collateral at 40–60% of NLV, leaving room for assignment and emergencies. Write your number in calm markets and enforce it in volatile ones.

How many contracts should I sell per underlying?

Common rules: one to three open short puts per ticker, with sector caps so correlated names do not stack. Size for one bad gap, not for perfect calm.

Is position sizing different for credit spreads?

Yes—max loss is spread width minus credit, so per-spread risk is defined. You may run more contracts than naked puts for the same dollar risk, but total book risk still needs a capcredit spreads vs puts.

How often should I review position sizing rules?

Weekly: sum collateral by expiration. Monthly: one rule change based on review. Quarterly: revisit max NLV percent if account size or strategy mix shifted.

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