XSP and SPY options both give a small account exposure to the S&P 500 at roughly the same scale, and this account has real, closed trades in both. The two are close enough in size that it’s tempting to treat them as interchangeable. They aren’t. The real differences, cash settlement versus physical delivery, European versus American exercise, and genuinely different tax treatment, matter more than which one happens to be a few points wider that day.
The size question, settled with real numbers
On July 14, 2026, this account sold two same-day XSP put credit spreads, strikes in the 745 to 749 range, for a combined $16.08. Across June and July, this account also ran five same-day SPY trades, strikes landing between 725 and 752, for a combined $27.50. Both sets of trades happened within weeks of each other, tracking the same underlying index, and the strike ranges are nearly identical. That’s not a coincidence: SPY trades at roughly 1/10 the S&P 500’s index level, and XSP (formally Mini-SPX) is built at 1/10 the S&P 500’s level by design. A single contract of either one ends up representing similar notional exposure. The real differences between them have nothing to do with size.
Settlement: cash vs. shares
XSP is cash-settled. At expiration, the difference between the strike and the index’s settlement value is paid or collected in cash, full stop. Nothing physical ever changes hands. SPY options are physically settled equity options: if a SPY option finishes in the money and isn’t closed first, actual shares of the SPY ETF are delivered or received, 100 shares per contract.
Exercise style: European vs. American, and the assignment risk that follows
XSP is European-style, which means it can only be exercised at expiration, never early. SPY options are American-style, which means a short SPY option can be assigned at any point before expiration, not just at the end. In practice this shows up most often around dividend dates or when a short option is deep in the money late in its cycle. None of this account’s five SPY trades were ever assigned; every one closed or expired cleanly. But the exposure to that risk was structurally present the whole time in a way it simply isn’t with XSP. Selling a same-day SPY credit spread carries a real, if usually small, chance of early assignment that a same-day XSP spread never does.
Tax treatment: this is where the real gap is
XSP, like its full-size sibling SPX, is a broad-based, cash-settled index option and qualifies for Section 1256 tax treatment: a 60/40 blend of long-term and short-term capital gains rates, regardless of how briefly the position was held. SPY options do not qualify, since SPY is an ETF rather than a broad-based index option, and get taxed under the standard short-term or long-term rule based on actual holding period. For a same-day, high-frequency strategy like the credit spreads in both of these trade sets, that difference in tax treatment compounds every single cycle. The full breakdown, including why this account’s SPX and /ES positions get the same Section 1256 treatment XSP does, is covered in how are options taxed.
Liquidity: the one place SPY still has an edge
SPY is one of the most heavily traded options products in the world, and that volume tends to produce tight bid-ask spreads even on small size. XSP has grown substantially in volume but still generally trades a wider spread than SPY on comparable strikes. For a small account trading modest size, that spread difference is a real, if usually small, cost to weigh against XSP’s settlement and tax advantages.
Which one this account actually uses
Both, depending on what’s available and what the moment calls for. The larger and more consistent share of this account’s 0DTE activity runs through SPX directly, covered in what is a 0DTE option, with SPY and XSP both appearing in the record as smaller, same-day plays. Knowing the real difference between the two, not just their similar size, is what actually matters when picking one over the other for a given trade.
Frequently asked questions
What is the difference between XSP and SPY options?
XSP (Mini-SPX) is a cash-settled, European-style index option on 1/10 the value of the S&P 500 Index; SPY options are American-style equity options on shares of the SPDR S&P 500 ETF. Despite tracking the same index at a similar scale, they differ in settlement (cash vs. shares), exercise style (can only be exercised at expiration vs. any time), and tax treatment (Section 1256 60/40 for XSP, standard short-term/long-term rules for SPY).
Is XSP or SPY bigger, in terms of notional value per contract?
They end up close to the same size in practice. SPY trades at roughly 1/10 the S&P 500's level and XSP is deliberately built at 1/10 the S&P 500 as well, so a single contract of either one represents similar notional exposure. This account's own trades in both landed in nearly the same strike range at the same time, confirming the sizes are comparable rather than one being meaningfully smaller.
Does XSP have assignment risk like SPY does?
No. XSP is European-style and cash-settled, meaning it can only be exercised at expiration and never results in shares changing hands, so there is no early assignment risk at all. SPY options are American-style, physically-settled equity options, which means a short SPY option can be assigned at any time before expiration, most commonly around dividends or when deep in the money late in an expiration cycle.
Which one is better for a small account?
Neither is objectively better; they fit different priorities. XSP's cash settlement and Section 1256 tax treatment make it simpler to hold through expiration without assignment risk, and its Section 1256 status can be a real tax advantage over SPY for a short-dated, high-frequency strategy. SPY's tighter bid-ask spreads and larger overall volume can make it easier to get filled at a fair price on small size. This account has traded both.