3,081 stocks rose as the S&P 500 finished unchanged and Nasdaq-100 neared a high

Nine of 19 U.S. mega-cap companies fell on Tuesday, among them Microsoft, Amazon, Alphabet, Meta Platforms and JPMorgan Chase, and that split held the S&P 500 at 7,764.27, down 0.01% at the close. The pause sits on a month in which the cap-weighted S&P 500 fund SPY rose 1.3% while the equal-weight version of the same 500 stocks, RSP, fell 3.6% and the Russell 2000 fund IWM dropped 4.0%.

A slight majority of stocks rose, small-caps with them. The Nasdaq-100 touched a 52-week high. After Monday's 1.55% jump in SPY, driven by Meta and the chipmakers, the cap-weighted index held that gain and went no further.

More stocks rose than fell, and both S&P 500 funds finished near unchanged

Of 5,862 U.S. common stocks listed on the NYSE, Nasdaq and NYSE American, 3,081 advanced, 2,530 declined and 251 were unchanged. That is a 52.6% advancer share, or 1.22 advancers for every decliner. Funds, foreign listings and other non-common symbols are outside that count.

RSP gained 0.04%. SPY was unchanged. The spread between them was 0.05 percentage points; the equal-weight board went nowhere.

The Dow industrials fund DIA fell 0.35%, tracking the Dow Jones Industrial Average's drop of 185 points to 51,863.69. Mega-caps as a group went 10 up, 9 down. The financials sector fund XLF fell 2.0%, with JPMorgan Chase down 3.4% and Charles Schwab down 6.1%. The technology sector fund XLK rose 0.72%. Inside SPY, Micron Technology and Nvidia's gains were offset by Amazon, JPMorgan Chase, Microsoft and Alphabet, and the fund finished unchanged.

Micron did the heavy lifting in the Nasdaq-100

The Nasdaq-100 rose 0.82% to 30,732.40 after trading as high as 30,770.63, matching its 52-week high. The Nasdaq-100 fund QQQ gained 0.81% and finished 0.16% below its own 52-week high.

That gain was not a committee vote. Micron Technology, 4.9% of QQQ and due to report on September 30, rose 5.0% and contributed 0.25 percentage points. SanDisk added another 0.07 after Rosenblatt Securities started coverage at buy with a $2,400 target, 27% above Tuesday's $1,887 close. Advanced Micro Devices and Nvidia contributed 0.06 and 0.05. Those four names produced 0.43 percentage points, more than half the fund’s rise.

Cisco Systems, 1.8% of the same fund, fell 4.5% and took back 0.08 percentage points after Piper Sandler cut its price target to $125 from $132, citing concern that industry growth is peaking. Amazon and Microsoft joined the drag.

Over five sessions QQQ gained 6.2%. Advanced Micro Devices, Micron, Intel and Nvidia contributed 3.27 percentage points of that rise.

Five sessions of Nasdaq-100, a month of equal-weight decline

Tuesday’s slight majority does not rewind the past month. QQQ is up 4.9% over one month and 6.2% over five sessions. RSP is down 3.6% over one month and 0.17% over five sessions, and still sits 4.8% below its 52-week high. IWM is down 4.0% over one month even after Tuesday. SPY is up 1.3% over one month, which is what concentration looks like when Nvidia is 8.1% of the fund and the top ten companies are 40.0%.

The five-session column is the tell. Cap-weight’s gain is mostly Monday. Nasdaq-100 kept going on Tuesday. Equal-weight did not.

If you hold SPY, Tuesday was a pause after a concentrated gift. If you hold RSP, you spent the session in place and still sit well below where the equal-weight S&P 500 traded a month ago. If you hold QQQ, you are a fraction of a percent from a 52-week high because memory and chip names, not the rest of the 5,862-stock board, extended a five-day run. The index headline said unchanged. The holdings said otherwise.