AI Research QQQ

QQQ top up-days vs top down-days: are they clustered within the same turbulent stretches?

QQQ’s single biggest up-day (+13.62% on 2025-04-09) landed within a few sessions of its single biggest down-day (-6.18% on 2025-04-04), which makes for a compelling anecdote — but is it the rule? We tested that directly by scanning roughly three years of daily returns (751 trading days), picking the ten largest up-days and ten largest down-days, and measuring the trading‑day distance from each extreme to its nearest opposite extreme.

The result is mixed. The median nearest‑opposite distance is 9.5 days (up→down) and 8.5 days (down→up); only 20% of top up-days and 40% of top down-days fall within three trading days of an opposite extreme, and the 20 extremes span 422 trading days (56.2% of the window). There are clear turbulent clusters (notably early April 2025), but most extremes are separated by about one to two weeks — a suggestive lean toward partial bundling, not a definitive collapse of the “just dodge the bad days” idea. Full methodology and charts follow below.

The research question

For QQQ over the past ~3 years, are its ten best single-day returns clustered right alongside its ten worst — close enough that sidestepping the crashes would also have cost you the rebounds? Thesis: the biggest up-days overwhelmingly land within a handful of sessions of the biggest down-days, both bunched into the same turbulent stretches, so the 'just dodge the bad days' market-timing fantasy collapses because the sharpest gains and losses come bundled together.

How this was measured

Resampled QQQ minute bars to daily closes over the last ~3 years (anchored to the latest available day), computed daily close-to-close returns, and identified the top-N up days and top-N down days (N up to 10, reduced if the sample is small). For each up-day, computed the trading-day distance to the nearest down-day among the N worst, and vice versa for each down-day to the nearest up-day. Summarized the distribution of nearest-opposite distances (median and share within 3 and 5 trading days) and showed category counts (≤1, ≤3, ≤5, ≤10, >10). Also reported the trading-day span from the earliest to latest of the 2N extremes relative to the full window to indicate whether extremes bunch into compact turbulent stretches.

The key numbers

Trading days analyzed
751
Window start 2023-06-01 to end 2026-05-29
Top up-days selected (N)
10
Capped at 10; reduced when sample is small
Top down-days selected (N)
10
Capped at 10; reduced when sample is small
Largest up-day return
13.6195%
Date: 2025-04-09
Largest down-day return
-6.1801%
Date: 2025-04-04
Median distance (up → nearest down)
9.50
N=10 up-days
Median distance (down → nearest up)
8.50
N=10 down-days
Up-days within 3 trading days of a down-day
20.0000%
2/10
Down-days within 3 trading days of an up-day
40.0000%
4/10
Event span share of window
56.1917%
Span 422 trading days from earliest to latest of the 2N extremes

Reading the numbers

Over 751 trading days we picked the 10 biggest up-days and 10 biggest down-days; the median distance from an up to the nearest down is 9.5 trading days (and 8.5 the other way). Only 2 of 10 up-days (20%) and 4 of 10 down-days (40%) fall within 3 trading days.

The charts

QQQ daily returns with top up/down days highlighted
What this chart says

This daily-return line flags the ten biggest gains and losses: the single biggest up-day was 13.62% (2025-04-09) and the single biggest down-day was -6.18% (2025-04-04), so the top up and top down are five trading days apart and visibly sit in the same early-April spike. The ten top up-days average 4.55% and the ten top down-days average -4.14%, so when extremes occur they tend to be large but not all are paired. Look at that early-April cluster as an example of gains and losses bunched together, but note the rest of the highlighted points are scattered through the three-year line.

Nearest opposite extreme: distance categories
What this chart says

This distance-count bar chart breaks where each extreme’s nearest opposite fell: five of the 20 extremes are within one trading day of an opposite extreme, and the bins show 9 of 20 lie more than 10 days apart. Put another way, only 2 of the 10 up-days are within three trading days of a down-day and 4 of 10 down-days are within three days of an up-day, so tight one-week pairings are a minority, not the rule.

Distribution of nearest-opposite distances
What this chart says

The box-style summaries show medians (reported elsewhere) around 9.5 days for up→down and 8.5 days for down→up, while the means are much larger (28.6 and 25.3 trading days) because a few extremes sit very far apart (max distances 92 and 81 days). That skew — short medians but long means and very large maxima — tells the story: some big gains and losses are bunched tightly (short distances), but many others are separated by weeks or months, so extremes are only partly bundled into turbulent stretches.

Top up-days and their nearest top down-day

up_dayup_retnearest_down_daynearest_down_rettrading_days_apart
2025-04-090.13622025-04-10-0.04911
2026-03-310.04342025-11-20-0.037388
2024-08-080.04292024-08-01-0.03845
2025-04-220.04262025-04-10-0.04917
2025-05-120.03882025-04-10-0.049121
2024-07-310.03232024-08-01-0.03841
2026-02-060.0312025-11-20-0.037352
2026-04-070.03082025-11-20-0.037392
2025-04-240.03072025-04-10-0.04919
2024-08-150.02642024-08-01-0.038410

Top down-days and their nearest top up-day

down_daydown_retnearest_up_daynearest_up_rettrading_days_apart
2025-04-04-0.06182025-04-090.13623
2025-04-10-0.04912025-04-090.13621
2025-03-10-0.04382025-04-090.136222
2025-04-08-0.04372025-04-090.13621
2025-04-02-0.03872025-04-090.13625
2024-08-01-0.03842024-07-310.03231
2025-11-20-0.03732026-02-060.03152
2025-10-10-0.03542026-02-060.03181
2024-09-03-0.0332024-08-150.026412
2024-12-18-0.03242025-04-090.136275

The takeaway

Short answer: partly — some of QQQ’s biggest up-days do sit in the same turbulent episodes as the biggest down-days, but overall the ten biggest gains are not overwhelmingly clustered next to the ten biggest losses. The largest up-day was +13.62% on 2025-04-09 and the largest down-day was -6.18% on 2025-04-04; the median nearest-opposite distances are 9.5 trading days (up→down) and 8.5 days (down→up). Only 2 of 10 top up-days (20%) and 4 of 10 top down-days (40%) fell within three trading days of an opposite extreme, and the 20 extremes span 422 trading days — 56.2% of the 751‑day window. That means there are tight clusters (notably early April 2025, where several extremes are 1–3 days apart) but most extremes are separated by about one to two weeks. Bottom line on strength: this is a suggestive lean in favor of partial bundling, not a conclusive refutation of timing — the signal is mixed and modest, so treat it as suggestive rather than definitive. Practical takeaway: dodging bad days would sometimes cause you to miss rapid rebounds, but it’s not a universal rule — the big wins and losses are clustered in some episodes and scattered in others.

The fine print