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Guides, explainers, and insights on converting between stock market indices, futures contracts, and ETFs.

Why QQQ Slightly Underperforms NDX Over Time

QQQ lags the Nasdaq-100 by approximately 0.15–0.20% per year. The 0.20% expense ratio is the dominant driver, partially offset by securities lending income. Learn why the common price-only comparison understates QQQ's true performance, and when QQQM is the smarter choice.

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SPX AM vs PM Settlement Options: Which Contracts Expire When

Monthly SPX options (third Friday) are AM-settled at the SOQ — a price you won't know until mid-morning. SPXW weeklies settle PM at the 4:00 ET close. Learn which contracts use each mechanism, when the last day to trade is, and why this matters critically for 0DTE strategies.

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ETF Tracking Error: Why SPY Never Perfectly Matches SPX

SPY tracks SPX closely but never perfectly. Expense ratios, dividend cash drag, reconstitution costs, and securities lending all contribute to the gap. Learn what drives SPY's tracking error, why the SPX/SPY ratio drifts above 10 over time, and what it means when you're converting or hedging between the index and ETF.

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Futures Basis Explained: Cost of Carry for Index Futures

Futures basis is the gap between ES and SPX driven by cost of carry — financing rate minus dividend yield. Learn the fair value formula, how basis decays to zero at expiration, what the roll costs you, and how to strip out carry to read pre-market direction correctly.

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How Many SPY Shares Equal One ES Futures Contract?

At SPX 5,500, one ES contract controls $275,000 in notional value — equivalent to roughly 500 shares of SPY. Walk through the exact math, see how it changes with market levels, and learn how to size your hedge using ES or MES contracts.

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SPX Gap vs ES Futures at Market Open: What Causes It

At 9:30 AM ET, SPX prints its first tick from individual stock opening auctions — not from ES. Learn why the cash index diverges from ES futures at the open, how the fair value formula predicts the gap, and what forces convergence within seconds.

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SPX Weekend Effect: Why Index Futures Move Friday to Monday

SPX closes Friday but ES futures keep trading until Sunday 5 PM ET and reopen Sunday at 6 PM — repricing every weekend news event before Monday's bell. Learn how the mechanical gap forms, how to read Sunday evening ES prices, and what the academic "weekend effect" actually means for modern markets.

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