SPX vs SPY Options: Which Should You Trade?

The wrong choice between SPX and SPY options can quietly reshape your risk, capital requirements, tax treatment, and expiration-week workflow. While both products track the S&P 500, the practical differences are significant: SPX contracts are larger, cash-settled, and European-style, while SPY options are ETF-based, physically settled, and subject to early assignment.¹ For traders comparing SPX vs SPY options, those structural details matter as much as the market direction call.

This guide breaks down how contract size, settlement mechanics, exercise rules, liquidity, bid-ask spreads, tax considerations, and weekly expirations affect real trading decisions. You’ll see why SPX may suit defined-risk premium sellers, portfolio hedgers, and traders seeking Section 1256 tax treatment, and why SPY can be a better fit for smaller accounts, share-based strategies, and highly flexible position management. We’ll also cover the operational implications for spreads, covered calls, assignment risk, and automated trading systems so you can choose the index-options vehicle that matches your strategy rather than simply trading the more familiar ticker.

SPX vs SPY Options at a Glance

The Core Difference: Index Options vs ETF Options

SPX options are options on the S&P 500 Index, a calculated benchmark rather than a tradable security. SPY options are options on shares of the SPDR S&P 500 ETF Trust, an exchange-traded fund designed to track the S&P 500.

Both products allow traders to express bullish, bearish, neutral, hedging, and income-oriented views on the S&P 500. A trader can buy calls for upside exposure, buy puts for downside protection, sell defined-risk credit spreads for premium income, or construct neutral positions such as iron condors. The operational difference is what happens at expiration or exercise.

SPX does not represent shares that can be delivered. SPX options are cash-settled: the final settlement value is converted into a cash debit or credit.² SPY options are tied to an ETF with deliverable shares. If a short SPY call is assigned, the writer may need to deliver 100 SPY shares per contract; if a long SPY put is exercised, the holder may sell 100 shares per contract.

The central decision framework is straightforward: SPX is generally designed for larger, cash-settled index exposure, while SPY provides smaller, share-based flexibility. For automated strategies, this affects position sizing, assignment handling, capital allocation, and expiration-day workflows. A system trading short SPY options must account for early assignment and possible stock positions; a comparable SPX system does not manage share delivery.

Quick Comparison Table for Active Traders

For example, if SPX is near 6,000 and SPY is near $600, one SPX contract represents approximately $600,000 of index exposure, while one SPY contract represents approximately $60,000. Both use a $100 multiplier, but the roughly 10-to-1 price relationship creates the practical position-size gap.

Automation rule: normalize signals by notional exposure rather than contract count, and let a tool handle the math with automatic position size calculation. A strategy allocating one SPX spread should not automatically allocate one SPY spread as an equivalent hedge or directional trade. Always confirm current option specifications, available strikes, expiration schedules, settlement conventions, and broker margin treatment with the exchange and your broker before deployment.

Contract Size and Capital Requirements

Why SPX Options Have About 10x the Exposure of SPY

Both SPX and SPY options use a 100 multiplier, but the underlying price level creates a major difference in practical exposure. If the S&P 500 index is near 5,000 and SPY is near 500, an SPX option represents an index level roughly 10 times larger than one share of SPY.

A one-point move in SPX is worth $100 per contract, because the SPX index multiplier is 100.³ A $1 move in SPY is also worth $100 per contract, because one SPY option controls 100 ETF shares. The difference is that comparable market moves are expressed very differently:

• A 1% move in SPX from 5,000 is 50 index points, or approximately $5,000 of movement per contract.
• A 1% move in SPY from 500 is $5 per share, or approximately $500 of movement per contract.

That makes one SPX contract roughly equivalent to 10 SPY contracts for directional index exposure. At these levels, one SPX contract represents about $500,000 of index notional (5,000 × $100), while one SPY contract represents approximately $50,000 of ETF notional (500 × 100).

This matters for automated strategies because SPX cannot be scaled below one contract. Premium outlay, defined-risk spread width, naked-option margin, and intraday mark-to-market swings can all become material quickly. A signal that justifies one SPY contract may imply substantially more portfolio exposure if executed as one SPX contract.

Position Sizing for Small and Large Accounts

SPY is generally more practical for smaller accounts and systems that require fine-grained risk controls. An automation engine can increase exposure from one to two to three SPY contracts as signal strength, volatility, or available buying power changes. That flexibility is useful when enforcing per-trade loss limits, sector caps, daily drawdown limits, or delta-based portfolio constraints.

For example, a strategy limited to $300 maximum loss per trade may be able to trade one or two narrow SPY vertical spreads. If SPY offers a $1-wide spread with a maximum loss near $100 before credit adjustments, the system can size precisely around its risk budget. In SPX, commonly available strike spacing and wider vertical structures can make the minimum one-lot spread exceed that same $300 limit. A $5-wide SPX vertical has a gross width of $500 per contract before accounting for premium received.

SPX becomes more efficient when an account routinely needs exposure equivalent to 10 or more SPY contracts. Instead of managing numerous SPY legs, fills, assignments, and contract-level adjustments, the system can use fewer SPX contracts to express similar index risk.

• Calculate maximum loss as (spread width − net credit) × 100 × quantity for credit spreads.
• Set quantity from the strategy’s loss budget and portfolio-level delta, vega, and gamma limits.
• Check buying-power impact and worst-case aggregate exposure before submitting orders.

Choose SPX or SPY after defining risk limits, spread widths, and required sizing precision, not solely because one contract appears cheaper or carries a lower quoted premium.

Settlement: Cash-Settled SPX vs Physical SPY Delivery

How Cash Settlement Works for SPX Options

SPX options are cash-settled. An in-the-money contract does not deliver shares of an index ETF because the S&P 500 Index itself is not a tradable security. Instead, the option’s intrinsic value is converted into a cash credit or debit using the applicable final settlement value and the standard $100 contract multiplier.⁴

For example, assume a trader holds one 5,000-strike SPX call that expires in the money and settles at 5,020. The call has 20 index points of intrinsic value:

(5,020 − 5,000) × $100 = $2,000

The long call holder receives $2,000 before commissions, fees, and any applicable tax considerations. The corresponding short call writer pays that amount. No SPY shares, S&P 500 component stocks, or residual equity positions appear in either account after settlement.

This structure is operationally useful for automated strategies. A system holding SPX contracts through expiration can model the expected cash settlement directly from intrinsic value rather than needing post-expiration logic to liquidate, hedge, or reconcile a resulting stock position. It also avoids accidental overnight exposure caused by an option exercise or assignment creating shares after the close.

Settlement timing remains contract-specific. Traditional standard monthly SPX options may use AM settlement, where the final settlement value is derived from opening prices of the component stocks on expiration morning. SPXW weekly options are generally PM-settled, using the index’s closing value on expiration day. This distinction can materially affect expiration risk: an AM-settled position may stop trading the prior afternoon but settle against the next morning’s opening calculation. Automation should identify the exact symbol, expiration, and settlement convention rather than assuming all SPX expirations behave identically.

• Store settlement type as contract metadata in the strategy engine.
• Calculate projected cash settlement using intrinsic value × $100.
• Apply separate exit rules for AM-settled and PM-settled expirations.

How Physical Settlement Works for SPY Options

SPY options are physically settled. Exercise or assignment results in delivery of 100 shares of SPY per contract.⁵ A long call exercises into the purchase of 100 SPY shares at the strike; a long put exercises into the sale of 100 shares at the strike. For short option sellers, assignment creates the opposite obligation.

For example, a trader short one in-the-money SPY 500 put at expiration can be assigned and required to buy 100 SPY shares at $500 per share, creating a $50,000 stock purchase obligation. This can occur even if the trader intended only to collect option premium and did not plan to hold ETF shares.

Physical delivery is often desirable for covered-call traders seeking to sell existing SPY shares at a target price, or cash-secured-put traders seeking to acquire SPY at a lower effective entry price. It requires tighter operational controls, however. An automated system should monitor near-expiration contracts, account buying power, share inventory, and after-hours price movement that can influence exercise decisions.

• Short calls can result in 100 shares being called away per contract.
• Short puts can result in 100 shares being purchased per contract.
• Flag contracts near expiration when expected assignment would exceed share, margin, or concentration limits.
• Do not assume an out-of-the-money SPY option is risk-free after the close; exercise decisions can be made after regular trading hours.

European vs American Exercise and Assignment Risk

SPX Uses European-Style Exercise

Standard SPX options use European-style exercise: the option holder can exercise only at expiration, not before. As a result, a trader who is short an SPX call or put does not face early assignment during the life of the contract.⁶

This is operationally important for short-premium strategies. A short SPX credit spread, iron condor, butterfly, or calendar position can be held and adjusted near expiration without the possibility that one short leg will be assigned unexpectedly overnight. An automated strategy does not need a pre-expiration assignment workflow for SPX positions, such as acquiring shares after short-call assignment or funding a stock purchase after short-put assignment.

For example, a trader short an SPX 5,000/4,990 put credit spread cannot be assigned on the 5,000 short put on Tuesday simply because SPX falls below that strike. The position remains an options position until expiration. This can simplify rule-based management systems that close, roll, or hedge positions based on delta, underlying level, days to expiration, or loss thresholds.

However, no early assignment does not mean no expiration risk. SPX options are cash-settled, and in-the-money contracts settle against the applicable settlement value at expiration. A short option can still create a cash debit, and a defined-risk spread can still realize its maximum loss. Traders must also account for settlement conventions: standard monthly SPX options use an AM settlement process, while many weekly SPX options settle PM. Automation should distinguish these products rather than treating all expirations as identical.

• Track the exact expiration and settlement type for every SPX series.
• Close or hedge short in-the-money positions before a strategy’s defined cutoff.
• Do not rely on the absence of early assignment as a reason to ignore expiration-day price and settlement-value risk.

SPY Uses American-Style Exercise

SPY options are American-style, meaning the holder may exercise at any time before expiration. Therefore, traders short SPY options can be assigned early.⁷ Assignment results in delivery or receipt of 100 SPY shares per contract: short calls can create a short-stock position, while short puts can create a long-stock position.

The most common early-assignment scenario involves short SPY calls immediately before an ex-dividend date. A call holder may exercise early to receive the upcoming dividend if the call’s remaining extrinsic value is less than the dividend value. For example, if SPY is trading at $600, a 590 call has only $0.05 of extrinsic value remaining, and the next dividend is $1.70 per share, early exercise may be economically rational. A trader short that call can be assigned before the ex-dividend date.

Short puts can also be assigned early, particularly when they are deeply in the money and have little remaining extrinsic value. Interest rates, financing costs, borrow conditions, and the economics of holding shares can make early put exercise attractive to the holder.

• Monitor SPY ex-dividend dates, especially for short in-the-money calls.
• Calculate remaining extrinsic value rather than using moneyness alone.
• Flag short contracts with low extrinsic value and high assignment exposure in automated risk systems.
• Ensure the account has sufficient buying power and stock-handling logic for potential 100-share assignment events.

SPX vs SPY Options Taxes: Section 1256 Matters

Potential 60/40 Tax Treatment for SPX Options

Standard SPX options are generally classified as qualifying broad-based index options and, subject to the applicable rules, are treated as Section 1256 contracts for U.S. federal income-tax purposes. This classification can materially affect the after-tax result of an active index-options strategy.

The commonly cited Section 1256 benefit is 60/40 capital-gains treatment: 60% of net gains or losses are treated as long-term capital gains or losses, and 40% are treated as short-term, regardless of how long the position was held.⁸ For example, a trader who opens and closes an SPX iron condor on the same day may still report 60% of the resulting net Section 1256 gain at long-term rates and 40% at short-term rates. This differs from the normal rule under which a same-day trade is entirely short-term.

Section 1256 contracts also generally use a year-end mark-to-market process. Open qualifying positions are generally treated as if they were sold at fair market value on the last business day of the tax year, with the resulting unrealized gain or loss included in that year’s tax reporting.⁹ The position is then treated as repurchased at that value for the following year. An automated trader carrying SPX spreads, long premium positions, or hedges across December 31 should therefore export and reconcile year-end broker valuations rather than relying only on realized-trade reports.

• Track SPX positions separately from ETF-option positions in your trading and tax records.
• Confirm that the specific contract traded is a qualifying broad-based index option; product labels and broker reporting should not be your only source of authority.
• Account for mark-to-market exposure when sizing year-end positions and estimating tax cash requirements.

Important tax disclaimer: Tax treatment depends on the contract, account structure, elections, jurisdiction, offsetting positions, and the trader’s individual circumstances. Tax rules, interpretations, and rates can change. Consult a qualified tax professional before making trading, accounting, or product-selection decisions based on Section 1256 treatment.

Why SPY Options Usually Receive Different Tax Treatment

SPY options are options on shares of the SPDR S&P 500 ETF Trust, making them equity ETF options rather than broad-based index options. They generally do not receive Section 1256 treatment. Instead, gains and losses are generally taxed under normal capital-gains rules based on the holding period.

For a SPY option held one year or less, gains are generally short-term capital gains. Because many active traders hold SPY contracts intraday, overnight, or for only a few weeks, their gains and losses often receive short-term treatment, subject to their specific facts and tax position. A trader who buys a SPY call on Monday and sells it Friday, for example, would generally have short-term treatment rather than a 60/40 allocation.

Do not select SPX or SPY solely because of tax treatment. Compare liquidity at your target strike and expiration, bid-ask spreads, contract multiplier, exercise and assignment exposure, strategy fit, account constraints, and the operational requirements of your automation. Tax efficiency matters, but it should be evaluated alongside execution quality and risk control with professional tax guidance.

Liquidity, Spreads, and Expiration Choices

Comparing SPX and SPY Options Liquidity

Both SPX and SPY are among the most actively traded U.S. options products, but neither is uniformly “more liquid” across every contract. Liquidity changes materially by strike, expiration, time of day, volatility regime, and whether the order is opening or closing. A near-the-money 0DTE SPXW contract may quote extremely tightly, while a far-out SPX monthly strike can be relatively sparse. The same pattern applies to SPY, particularly in less-active strikes or longer-dated expirations.

Evaluate the exact contract you intend to trade rather than relying on aggregate volume statistics. Compare the quoted bid-ask spread, displayed bid and offer size, open interest, recent trade activity, and, most importantly, the quality of actual fills. A $0.10 displayed spread is not necessarily executable at the midpoint, especially during rapid index moves or around economic releases.

• SPX can accommodate institutional-scale orders efficiently in actively traded strikes and is cash settled, eliminating ETF-share delivery concerns.
• SPY has a contract multiplier of 100 shares of a much lower-priced underlying, allowing smaller accounts to size positions more precisely.
• Automation rule: capture the live NBBO, displayed size, and recent fill data by strike and expiration. Do not assume a historical mid-price is tradable.

For multi-leg spreads, iron condors, calendars, and butterflies, use limit orders. A backtest that marks each leg at the midpoint can materially overstate realized performance. Model a conservative fill assumption, such as paying a defined percentage of the quoted spread or using observed order-level fill data, then validate it in live or paper execution.

Daily, Weekly, and Monthly Expirations

SPX offers frequent expirations through SPXW contracts, including daily and weekly listings, while SPY also has highly active weekly and monthly expirations. Automation can target these short-dated series by automating options trades with dynamic expirations so the system always selects the intended contract. Short-dated contracts create more entry opportunities and faster premium decay, but they also introduce higher gamma risk: a small underlying move can produce a large change in delta and position value. This leaves less time to correct pricing errors, manage breached strikes, or recover from delayed order execution.

Contract selection matters especially in SPX. Standard monthly SPX options are generally AM settled, with trading ending on the Thursday before the Friday settlement value is calculated. SPXW contracts are generally PM settled and trade through the expiration day. These are different risk exposures; an overnight gap can affect an AM-settled position even though it cannot be traded during the Friday morning settlement process.

Before transmitting an automated order, require a pre-trade validation checklist:

• Confirm the ticker: SPX versus SPXW versus SPY.
• Confirm the exact strike and expiration date.
• Verify AM versus PM settlement.
• Verify call or put, buy or sell direction, and contract multiplier.
• Confirm quantity and total notional exposure.
• Calculate the strategy’s maximum loss, including a conservative execution-cost assumption.

Which Is Better for Automated Options Trading?

When SPX May Fit an Automated Strategy

SPX options are generally better suited to automated strategies with larger capital allocations, defined-risk index spreads, and a preference for cash settlement. SPX is European-style, so it cannot be exercised early; all exercise and assignment occurs at expiration, with settlement in cash rather than delivery of ETF shares. This removes an important operational branch from an automated system: there is no need to manage unexpected stock positions from early assignment.

Because one SPX contract represents a substantially larger notional S&P 500 exposure than one SPY contract, SPX can reduce contract-count complexity. A strategy seeking approximately the exposure of ten SPY contracts can often express that view with one SPX contract. However, this also means that a one-contract adjustment can materially change account risk. Position-sizing logic must enforce dollar-based limits, not merely contract limits.

For example, a systematic iron condor strategy may prefer SPX because a short spread cannot result in ETF share delivery and because early assignment is not possible. The system should still verify that the maximum loss of one condor fits the account-level risk limit before transmitting an order. If the minimum one-lot SPX position exceeds the permitted loss, the trade should be rejected rather than rounded up.

When SPY May Fit an Automated Strategy

SPY options are often more practical for smaller accounts and systems that need fine-grained scaling. SPY options are physically settled and American-style, allowing early exercise and assignment. Their smaller per-contract exposure lets an algorithm move from one to two contracts rather than making an approximately tenfold exposure jump associated with moving from one SPY contract to one SPX contract.

SPY also fits strategies that intentionally interact with ETF shares, including covered calls, cash-secured puts, wheel strategies, and workflows that may hold shares after expiration. The automation burden is higher: the system must monitor short in-the-money options, account buying power, ex-dividend dates, dividend-related early assignment risk on short calls, and post-expiration stock positions.

For example, a signal-driven bull put spread system with a strict $500 maximum loss per trade may fit SPY better than SPX. If the narrowest acceptable SPX vertical spread has a maximum loss above $500, the system cannot comply with its risk budget. A one-lot SPY spread may allow the strategy to select a width and quantity that remain within the cap.

Automation Checklist Before Sending a Live Options Alert

• Define the contract precisely: SPX or SPY, expiration or days-to-expiration range, call or put, strike-selection rule, and whether the order is single-leg or multi-leg.
• Specify selection logic such as target delta, percentage out-of-the-money, expected-move distance, spread width, minimum open interest, maximum bid-ask spread, and minimum credit or maximum debit.
• Enforce hard limits for maximum contracts, maximum defined loss per trade, maximum aggregate position risk, and maximum daily realized-plus-unrealized loss.
• Set a no-new-trades cutoff before expiration, particularly for SPY positions that could create assignment or share-delivery exposure.
• Define exits for profit targets, stop losses, time stops, signal reversals, and short-option delta thresholds, such as an automated exit strategy using relative stop loss and take profit. Include explicit handling for rejected, partially filled, and legged orders.
• Paper trade the complete workflow, then validate at small size. Log every alert, market-data input, order submission, fill, cancellation, and risk-rule override.
• Maintain a manual contingency procedure for brokerage, market-data, platform, or connectivity outages, including who can close positions and under what conditions.

SPX vs SPY Options: The Bottom Line

Choose SPX If You Prioritize Cash Settlement and Scale

SPX options are generally the better fit when the strategy requires index-level exposure, cash settlement, and no post-expiration stock position. Each SPX contract has a $100 multiplier on the S&P 500 Index, while SPY options reference an ETF priced at roughly one-tenth of the index level. As a result, one SPX contract typically carries approximately 10 times the notional exposure of one SPY contract.

That scale is efficient for traders managing larger portfolios or automating strategies that would otherwise require multiple SPY contracts. For example, if SPY trades near $600 and SPX trades near 6,000, a 10-point move in SPX is worth approximately $1,000 per contract, while a comparable 1-point move in SPY is worth approximately $100 per contract. A system that sells a one-lot SPX credit spread must therefore size width, premium targets, and stop thresholds for materially larger dollar swings.

• Settlement: SPX options settle in cash; an in-the-money expiration produces a cash debit or credit rather than delivery of shares.
• Exercise style: SPX options are European-style, so holders cannot exercise before expiration. Short positions do not face early assignment.
• Tax treatment: Broad-based index options such as SPX may qualify for Section 1256 treatment, generally using a 60% long-term and 40% short-term capital-gains allocation regardless of holding period. Confirm eligibility and treatment with a qualified tax adviser.

The larger contract is not automatically preferable. A $5-wide SPX vertical spread has a maximum width-based risk of $500 per contract before credit, compared with roughly $50 for an equivalent $5-wide SPY spread. If the smallest viable SPX position exceeds the strategy’s risk budget, SPY is the more appropriate instrument.

Automation must also distinguish expiration conventions. Standard monthly SPX contracts have historically used AM settlement based on the Special Opening Quotation, while SPXW weekly and daily-expiring contracts are generally PM settled. Do not assume that a position can be closed at Friday’s regular-session close simply because its expiration date is Friday. The trading cutoff, settlement value, and final risk window must be encoded separately for each series.

Choose SPY If You Need Smaller Position Increments

SPY options are usually the better fit for traders who need granular sizing. Because one SPY option represents 100 ETF shares, a trader can scale exposure in smaller increments, test automated execution logic with lower dollar risk, and construct positions that would be oversized in a single SPX contract.

SPY is also the practical choice for strategies involving ETF-share delivery, including covered calls, cash-secured puts, collars, and stock-plus-option overlays. A short SPY call that is assigned requires delivery of 100 SPY shares per contract; a short put assignment creates a 100-share long position. That outcome can be intentional in a covered-call program, but it must be reflected in buying-power, inventory, and liquidation logic.

• Early assignment risk: SPY options are American-style and may be exercised before expiration.
• Dividend sensitivity: Short in-the-money calls face elevated assignment risk before an ex-dividend date when remaining extrinsic value is less than the dividend.
• Operational controls: Automated systems should monitor ex-dividend dates, short-option extrinsic value, account share inventory, and assignment notifications.

The practical rule is straightforward: choose the product that keeps the strategy’s worst-case loss, execution process, and expiration-management plan within defined limits. If one SPX contract is too large or AM-settlement handling introduces unacceptable operational complexity, use SPY. If share assignment is undesirable and the strategy needs larger cash-settled index exposure, use SPX.

Frequently Asked Questions

Is SPX 10 times bigger than SPY options?

In practical notional exposure, one SPX options contract is typically about 10 times larger than one SPY options contract. Both generally use a $100 contract multiplier, but the SPX index is usually priced near 10 times the price of SPY. As a result, each point of SPX movement represents substantially more dollar exposure. The exact relationship can vary slightly as SPX and SPY prices move.

Are SPX options better than SPY options?

Neither product is universally better. The better choice depends on your account size, strategy, tax situation, comfort with assignment risk, and need for precise position sizing. SPX options can suit larger accounts and cash-settled, defined-risk index strategies. SPY options may be more practical for smaller accounts, traders who want one-contract scaling, or strategies that benefit from ETF share delivery at exercise or assignment.

Can SPX options be assigned early?

Generally, no. SPX options use European-style exercise, meaning they cannot be exercised early before expiration. As a result, traders who sell SPX options typically do not face early assignment risk. However, that does not eliminate all expiration-related considerations. Traders should still monitor in-the-money positions, understand settlement procedures, and manage the potential impact of expiration-day price movement and cash settlement.

Do SPX options have Section 1256 tax treatment?

Qualifying SPX broad-based index options are generally treated as Section 1256 contracts for U.S. tax purposes. This treatment commonly applies a 60% long-term and 40% short-term capital gains split, regardless of the holding period, and generally requires year-end mark-to-market treatment. Tax rules can be complex and individual outcomes vary, so consult a qualified tax professional before making trading decisions based on tax treatment.

Can you automate SPX or SPY options trading?

Yes, automation may be possible when your trading platform, broker connection, account permissions, and supported order types align with your strategy. Before enabling live automation, define your contract-selection process, position size, entry criteria, exit rules, expiration handling, and risk safeguards. Test the workflow in a simulator or with small position sizes first, and confirm that your broker supports the specific SPX or SPY options orders and automation tools you plan to use.

Conclusion

SPX and SPY options can both support sophisticated strategies, but they solve different problems. SPX offers cash settlement, European-style exercise, and favorable tax treatment for many U.S. traders, making it compelling for index-level hedging and defined-risk positions. SPY provides smaller contract sizing, deep liquidity, and share-based settlement, which can make it more accessible for traders who need flexibility or want to manage positions around ETF shares.

The better choice depends on your account size, strategy, assignment tolerance, tax considerations, and broker’s available option symbols and order support. For automation, those operational details matter as much as the contract itself. Explore TradersPost to automate trading options on TradingView and route alerts to supported brokers, then thoroughly test position sizing, risk controls, fills, and broker-specific SPX or SPY options support before going live. Build the workflow carefully, validate it in real conditions, and trade with confidence.

References

¹ Cboe: Why Option Settlement Style Matters
² Cboe: Why Option Settlement Style Matters
³ Cboe: S&P 500 Index Options (SPX) Product Specifications
⁴ Cboe: S&P 500 Index Options (SPX) Product Specifications
⁵ Cboe: Why Option Settlement Style Matters
⁶ Cboe: Why Trade XSP vs. SPY: A Breakdown of the Benefits
⁷ Cboe: Why Trade XSP vs. SPY: A Breakdown of the Benefits
⁸ Cboe: Mini-SPX (XSP) Index Options Tax Benefit
⁹ 26 U.S. Code § 1256, Section 1256 Contracts Marked to Market