The Nasdaq Composite lost 4.48% in the week to Friday 16 October 2026, closing at 26,140.03 (Associated Press figures reproduced by Vista Partners), while bitcoin lost 1.70% Friday to Friday on Coinbase. Traders are asking the obvious question for the week ahead: does a big stock-market drop tell us anything about what bitcoin does next? We tested it on 520 weeks of data back to October 2016. In the 55 weeks when the Nasdaq fell 3% or more, bitcoin fell in the same week 39 times, averaging −3.59%. The following week it rose 31 times, averaging +1.98%, which is not distinguishable from an ordinary week (+1.36%).
How we measured it
We took the Nasdaq Composite (^IXIC) close on the last trading day of each ISO week from Yahoo Finance and computed its weekly change. For bitcoin we used the Yahoo Finance BTC-USD daily close on the same dates (a UTC-day close) and computed the change over the same two Fridays, then the change over the following week. That gives 520 weeks with complete data, from the week ending 28 October 2016 to the week ending 9 October 2026, each with a “same week” and a “next week” bitcoin return. We then grouped the weeks by the size of the Nasdaq move. All figures are percentages; “SE” is the standard error of the mean, a rough guide to how much an average could wobble by chance.
The result: a clear same-week link, no clear next-week one
| Nasdaq weekly move | Weeks | Bitcoin same week: mean / median / weeks up | Bitcoin next week: mean / median / weeks up |
|---|---|---|---|
| All weeks | 520 | +1.38% / +0.62% / 281 | +1.36% / +0.61% / 280 |
| −2% or worse | 96 | −2.86% / −1.88% / 33 | +1.09% / +0.20% / 50 |
| −3% or worse | 55 | −3.59% / −2.40% / 16 | +1.98% / +0.83% / 31 |
| +3% or better | 73 | +3.74% / +2.40% / 47 | +1.35% / +1.59% / 44 |
Two things stand out. First, in the same week bitcoin and the Nasdaq move together far more often than not: after a 3% Nasdaq drop bitcoin was down in 39 of 55 weeks (71%), against a normal share of down weeks of about 46%. The weekly correlation across all 520 weeks is +0.21, modest but positive. Second, the following week looks like any other week. Bitcoin rose in 31 of 55 weeks (56%) after a 3% Nasdaq drop, against 54% (280 of 520) in all weeks. The average, +1.98% with a standard error of 1.33, is higher than the all-weeks +1.36%, but the difference is about half of one standard error, which is noise.
Does it hold across different periods?
| Period (Nasdaq −3% or worse weeks) | Weeks | Bitcoin next week: mean / median / weeks up |
|---|---|---|
| 2016–2021 | 21 | +3.72% / +4.37% / 14 |
| 2022–2026 | 34 | +0.91% / +0.31% / 17 |
| 2024–2026 only | 13 | +1.29% / +0.83% / 7 |
This is where the sample reveals a weakness. The average in the early years, which includes the 2020 and early-2021 rebounds, was +3.72% with 14 of 21 weeks higher. Since 2022 the picture is a coin flip: 17 of 34 weeks higher and a median of +0.31%. Nine of the 55 weeks also directly followed another qualifying week, so the observations are not independent; June 2022 alone supplies a −29.6% bitcoin week followed by a +3.7% one. Removing the three best and three worst next-week results leaves an average of +2.23%, so a few extreme weeks are not what drives the average, but the median since 2022 says there is no reliable bounce to bank on.
What about weeks when bitcoin held up better than stocks?
This week is that case: the Nasdaq fell 4.48% and bitcoin only 1.70%. We checked the 33 weeks in our sample where the Nasdaq fell 3% or more and bitcoin’s same-week change was better than the Nasdaq’s. The next week averaged +1.37% (median +0.70%) with 18 of 33 up. That is also close to the all-weeks baseline. Relative strength in a bad stock week has not, in this sample, been a reliable sign of what comes next.
How this week fits
The Nasdaq’s weekly drop was driven by worries about how AI infrastructure is financed, with CoreWeave’s roughly $50 billion of debt at the centre, plus Brent crude at $109.86 and a 10-year Treasury yield of 5.097% (see our Saturday report). Our earlier daily studies found that bitcoin averaged −2.70% on the 26 days the VIX jumped 10% or more (VIX analysis) and −1.07% on days a semiconductor ETF fell 2% or more. This weekly test adds a longer-horizon check: the link is a same-week effect. It does not predict a rebound or a second leg lower.
Limits of this test
Weekly stock closes are at 20:00 UTC on Fridays in summer (4 p.m. New York time), while the Yahoo bitcoin close is a UTC-day close, so the two series are aligned by date and not by minute. Yahoo’s BTC-USD closes differ slightly from Coinbase’s: on Yahoo the week to 16 October was −1.27% against −1.70% on Coinbase. We selected the −3% threshold after seeing the Nasdaq’s −4.48% week, so it is a convenient cut, not a pre-registered one; the −2% group gives the same conclusion (next week +1.09%, 50 of 96 up). Overlapping weeks, sample size and the regime changes between 2018, 2022 and 2026 all limit what can be said. The test shows an association, not a cause.
What to watch next
Netflix reports after the close on Tuesday 20 October and Meta, Tesla, IBM and Texas Instruments after the close on Wednesday 21 October, according to a 17 October preview by Opening Bell Daily; the Fed meets on 27–28 October. Bitcoin traded near $81,660 at 06:04 UTC on Sunday on the Coinbase ticker, after closing Saturday at $81,378. If the history above is any guide, the stock market’s Friday matters mainly for the week it happened in.
Method: bitcoin prices, highs, lows and closes are Coinbase Exchange candles (UTC day or UTC hour) pulled by Bitcoin Mastery at about 06:05 UTC on Sunday 18 October 2026; the 18 October candle is still open at that time, so any closing figure quoted is the 17 October close unless stated. Index, stock and yield figures are Yahoo Finance daily data or the news sources cited; other third-party figures are attributed to their source and date. Weekly Nasdaq and bitcoin changes use Yahoo Finance daily closes (^IXIC and BTC-USD) for 520 weeks from 28 October 2016 to 9 October 2026 plus the following week; the current week’s Nasdaq figure is from AP via Vista Partners and bitcoin’s from Coinbase Friday-to-Friday closes. “Held up better” means bitcoin’s same-week change exceeded the Nasdaq’s.
Disclaimer: This article is for informational purposes only and does not constitute investment advice. Bitcoin and other cryptocurrencies are volatile and you can lose some or all of the money you put in. Nothing here is a recommendation to buy, sell or hold bitcoin, any exchange-traded fund, any listed security or any other asset, and the technical levels, probabilities and scenarios discussed are descriptions of published data, not forecasts. Do your own research and consult a licensed financial advisor before making investment decisions.