Published Oct 9, 2026, 4:39 PM ET
Today's move, what drove it, and what the available information cannot explain.
Capitalisation weighted, so a move in the largest companies moves it more than a move in the smallest.
Every Nasdaq listing, weighted by capitalisation and heavy in technology.
Thirty names weighted by price rather than by capitalisation, so it can disagree with the S&P for arithmetic reasons alone.
Small capitalisation names. Read against the S&P, it is the size half of how broad a day was.
The same five hundred companies weighted equally, so the largest names count no more than the smallest. Read against the cap-weighted index, the gap is how much of the day belonged to the biggest companies.
The two moved together, so the session was not a story about the largest companies.
38%
3 of 8 tracked indices above their 50-day average
Counted over ^GSPC, ^IXIC, ^DJI, ^RUT, ^FTSE, ^N225, ^GDAXI, 000001.SS. This is a reading across whole market indices, not a count of the companies inside any one of them.
CNN's own index, stored at the close. Context for whether sentiment confirms the tape or contradicts it.
Expected thirty day volatility from S&P 500 options. Rising with the index is the contradiction worth seeing.
The evidence read for this company over the 7 days before the session was its own SEC filings, its stored corporate actions, the headline feed collected for its ticker, the clustered news events this system collects every two hours across every category and the same events that name the company in their own text. None of them holds a row for this company inside that window.
Moved 6.0%, at or above the 3% floor for this strip
An analyst turned bullish on Palantir the same day shares jumped, a plausible same-day catalyst.
News event dated 2026-10-09, MarketWatch Top Stories: Analyst Turns Bullish on Palantir
Moved 5.2%, at or above the 3% floor for this strip
Same-day coverage tied GameStop's gain to continued insider buying momentum keeping traders engaged.
Headline dated 2026-10-09: GameStop Gains as Insider Buying Momentum Keeps Traders Engaged - Quiver Quantitative
Moved 5.1%, at or above the 3% floor for this strip
Google's nuclear power deal with Constellation, reported two days earlier, remained a live driver of the stock's advance.
News event dated 2026-10-07, CNBC Top News: Google strikes nuclear power deal with Constellation amid AI energy crunch
Moved 4.6%, at or above the 3% floor for this strip
Same-day headline directly asked why Coinbase stock was surging that Friday session.
Headline dated 2026-10-09: Why Is Coinbase Stock Surging Friday? - Benzinga
Moved 4.3%, at or above the 3% floor for this strip
Same-day headline asked what was going on with Amazon stock that Friday, matching the move.
Headline dated 2026-10-09: What's Going On With Amazon Stock Friday? - Amazon.com (NASDAQ:AMZN) - Benzinga
Moved 3.3%, at or above the 3% floor for this strip
Built in code from the movers whose evidence did not resolve, so no written summary can shorten this list.
The S&P 500 rose 0.59% while the equal weight fund rose 0.55%, only a 0.04 point gap, suggesting the advance was broadly shared rather than concentrated in a few names.
The Dow Jones gained 0.83% and the Nasdaq Composite gained 0.64%, both ahead of the Russell 2000's 0.46%, showing large caps and tech leading small caps rather than lagging them.
Sector returns ranged from Real Estate up 1.86% to Communication Services down 1.51%, a spread wide enough to show rotation beneath a positive headline index move.
Participation held at 3 of 8 tracked indices above their 50-day average, unchanged from the prior session even though the S&P 500 advanced, indicating breadth did not improve alongside the gain.
One session, from the stored closes of the eleven sector ETFs. Each bar is scaled against the widest move of the day, so the shape is the spread and not an absolute size.