Special Quotation (SQ)

For traders working with equity index futures and options — whether on Nikkei 225 in Japan or on S&P 500 in the United States — the Special Quotation (SQ) is an unavoidable concept. SQ is the final settlement price for expiring contracts, and the period around an SQ session frequently brings outsized volatility and volume.

Understanding what SQ is, how it is calculated, and how it shapes market behavior helps traders manage timing risk and avoid being caught wrong-footed at expiration.

This article walks through the SQ concept end-to-end, covering both the Japanese (Nikkei 225 SQ) and US (CME / CBOE SOQ) markets, with practical takeaways for short-term traders and long-horizon investors.

1. What Is the Special Quotation (SQ)?

The Special Quotation (SQ) is the final settlement price for expiring stock index futures and options contracts. The term originated in Japan, where it is widely used for Nikkei 225 futures and Nikkei 225 options at the Osaka Exchange (OSE). In the US, the equivalent concept is called the Special Opening Quotation (SOQ), used by CME Group for S&P 500 futures and by CBOE for SPX options.

Open positions remaining at expiration are settled at the SQ value automatically. So the SQ price directly determines the final P&L of any open futures or options exposure at the time of expiry.

Major SQ vs Minor SQ (Japan)

In the Japanese market, SQ occurs every month, but its market impact differs by month.

Major SQ

Falls on the second Friday of March, June, September, and December. Both index futures and index options expire together, so capital moves are large and the opening session typically sees pronounced moves and volume.

Minor SQ

Falls on the second Friday of the other months (Jan / Feb / Apr / May / Jul / Aug / Oct / Nov), when only options expire. Market impact is generally smaller than Major SQ.

In US markets, the analogous concept is Triple Witching, when stock options, equity index futures, and equity index options all expire on the third Friday of March, June, September, and December.

2. How SQ Is Calculated: Opening-Price Weighted Average

SQ is calculated on the morning of the expiration Friday, using the opening prices of the underlying index constituents.

For Nikkei 225 SQ, the calculation uses the opening prices of all 225 component stocks on the second Friday, weighted by the index's standard weighting rules. For US S&P 500 futures, the SOQ is calculated similarly from the opening prices of the 500 constituents at the New York open. If some constituent stocks fail to open at the regular time, the SQ / SOQ value is not finalized until every constituent has printed an opening price.

For settlement: open options positions are settled at SQ to determine final P&L for both writer and buyer; open futures positions are auto-closed at the SQ price. Because market participants try to anticipate the SQ price and position for it, both volume and volatility tend to be elevated on and around the expiration session.

3. Three Ways SQ Affects the Market

SQ's market impact can be decomposed into three layers: price volatility, trading volume, and capital flow (rollover).

Effect 1: Opening-Print Volatility Tends to Expand

On the SQ day, particularly during the opening session, price moves tend to be larger than usual. Many futures and options open positions get settled at the open, so trader orders concentrate around the opening print. This concentration easily produces gap moves up or down, and is often accompanied by elevated volatility.

Effect 2: Trading Volume Spikes Notably

In the SQ week, especially on the settlement day, total market volume runs well above normal. Institutional desks, arbitrage traders, and algorithmic strategies tend to settle or roll positions at this time, releasing a large volume of trades into a short window.

Effect 3: Rollover Reshapes Capital Flow

Once expiring contracts settle, capital quickly migrates to the next contract month — the rollover (roll) process. Major SQ events involve particularly large rollovers and can shift overall capital flow patterns, occasionally moving the short-term index trend.

4. Typical Phenomena on SQ Day

A few patterns recur on SQ settlement days. First, opening-session volatility expansion: open futures and options settle at the open, releasing concentrated buy and sell pressure that produces gap moves or rapid swings. Second, volume surge: institutional positioning and algorithmic activity intensify around expiration, lifting volume well above average. Third, short-term price distortions: high-weight constituent stocks can be aggressively bid up or sold down at the open, with the price effect normally fading later in the session.

5. Historical SQ Cases: 2008 Crisis and 2020 COVID Shock

Case 1: SQ Day During the 2008 Financial Crisis

During the 2008 global financial crisis, market sentiment was deeply fearful. Many large institutions chose SQ days for major position liquidation. On a notable US settlement day, the equity index futures and options markets faced enormous selling pressure, the S&P 500 gapped down at the open, volume spiked, and the market briefly traded with disorderly price action. The episode reinforced the importance of monitoring SQ-related liquidity shocks and short-term risk.

Case 2: SQ Day in the Early COVID-19 Period (2020)

In early 2020, as COVID-19 spread, market uncertainty was extreme. The SQ day in this period produced historically rare volatility. Panic selling and rapid capital reallocation drove S&P 500 futures sharply lower at the open, and trading volume hit record highs. Many investors slashed or rolled positions in haste, capital moved through the market at high speed, and the index swung violently in a short time. That session became a defining moment of that year's volatility regime.

Case 3: Smaller Swings in Normal Times

Even in calm periods, SQ days can deliver short bursts of volatility. Some institutional desks concentrate position handling at the opening of the settlement day, briefly pushing or pulling high-weight constituent stocks. Such effects are most visible on Major SQ days each year, and usually fade later in the session as the market normalizes.

6. Practical Notes for Trading Around SQ

6.1 SQ Value vs the Previous Close

SQ is determined at the opening print, so the gap between the prior day's close and the SQ value is often discussed in market commentary. A wide gap can reflect the unwinding of basis arbitrage positions in the futures market.

6.2 What to Watch in Major SQ Week

In a Major SQ week, rollover activity tends to concentrate around the close on Wednesday and Thursday. Watching spreads and volume in those windows can help build a sense of what to expect at SQ open. For US markets, the same applies to the Triple Witching week.

6.3 Open Interest and Strike Concentration

Whether SQ lands at, above, or below specific option strikes meaningfully changes P&L for both buyers and writers. Reviewing open interest (OI) and strike concentration in the week before settlement can help estimate "magnet" levels for the SQ print.

7. Frequently Asked Questions

Q1: Does an SQ day always produce big moves?

Not necessarily. SQ days tend to be more volatile than normal, but whether a session is dramatically volatile or relatively quiet depends on the prevailing market sentiment and how much pre-positioning has already happened. If the trend is well established and institutions have rolled positions in advance, the actual SQ session can be fairly orderly.

Q2: Do retail investors need to do anything special on SQ day?

Short-term traders should treat SQ days with elevated risk awareness because unexpected moves are more likely. Long-horizon investors do not need to overreact — staying calm and watching the market with normal attention is usually enough.

Q3: How can investors check the SQ schedule?

Each exchange publishes the annual SQ schedule in advance. In Japan the Osaka Exchange (OSE) publishes its calendar; in the US the CME Group and CBOE publish settlement schedules. The general rule of thumb is the second Friday of the month in Japan and the third Friday in the US.

Q4: What is the difference between Japanese SQ and US SOQ / Triple Witching?

Conceptually they are the same — both are settlement prices based on the opening prices of constituent stocks. Mechanically, US Triple Witching falls on the third Friday of March / June / September / December and involves stock options, equity index futures, and equity index options simultaneously expiring; Japan's Major SQ falls on the second Friday and is dominated by Nikkei 225 futures and options.

Q5: Where can SQ values be confirmed?

Confirmed SQ values are published by the relevant exchange (Osaka Exchange for Japan, CME / CBOE for the US) and disseminated through major market data outlets and broker platforms. In Japan, an early "preliminary" value is typically available shortly after the open, with the "final" value published once all constituents have priced.

8. Summary: Reading Market Rhythm Through SQ

The Special Quotation (SQ) is the final settlement price for expiring index futures and options. It has a measurable, repeatable impact on short-term market behavior — through opening-print volatility, volume surges, and capital rollover.

Understanding the calculation methodology (opening-price weighted average), the timing of impact (Major SQ week and the SQ open), and the typical patterns (volatility, volume, rollover) helps traders manage risk during high-volatility windows while also reading the market's rhythm to inform decisions.

Major SQ weeks in particular concentrate capital flow and price movement, and deserve close attention from both short-term and long-horizon participants. Understanding SQ is one practical way to read the market's underlying rhythm and to make better decisions when it matters most.

---

Further Reading

• Nikkei 225: Index Composition and Futures / Options Basics
• What Is Volatility?
• What Is a Stop-Loss?
• What Is a Zero-Sum Game?
• What Is a CFD?
• Forex Trading Basics
• What Is Leverage?

---

Primary Sources by Category

• Japan market (Nikkei 225 SQ): Osaka Exchange (OSE) "Special Quotation" official methodology; SBI Securities, Matsui Securities, SMBC Nikko Securities SQ explainer FAQs; Nikkei "SQ explainer" terminology references
• US market (SOQ, S&P 500): CME Group "Final Settlement Procedures" and "Understanding the Special Opening Quotation (SOQ)"; SEC / CFTC 1987 SOQ transition announcements; CBOE "Settlement of Standard, A.M.-Settled S&P 500 Index Options"
• Arbitrage and rollover research: Hull, J. C. Options, Futures, and Other Derivatives; JPX self-research reports on basis arbitrage and SQ analytics
• Historical case data: Market data from CME and Osaka Exchange covering the 2008 Financial Crisis and 2020 COVID-19 periods