Market breadth measures how many stocks take part in a market move. In 2026, most S&P 500 stocks have trailed the index. The S&P 500 is up 11.4% this year through the October 23, 2026, close, but only 217 of the 500 stocks that traded all year are beating it. Breadth has widened since September 30, though.
By Opening Bell Daily Staff. Updated October 24, 2026, with data through the October 23, 2026, close.
What is market breadth?
Market breadth tells you whether a rally is broad or carried by a few names. It looks past the index level and counts how many stocks are actually doing the work.
The S&P 500 weights each company by its market value, so a handful of giants can lift the index while most stocks go nowhere. A broad market has most stocks rising together. A narrow market has the index climbing on the backs of a few large companies.
That's why most stocks can lag the S&P 500 in a year when the index looks strong.
How is market breadth measured?
There are four common ways to measure breadth. Each one asks the same question from a different angle.
The advance-decline line
Each day, take the number of stocks that rose and subtract the number that fell, then add the result to a running total. A rising advance-decline line means more stocks are going up than down over time. When the index hits new highs and the line doesn't, breadth is weakening.
On October 23, 2026, 135 of the 503 S&P 500 stocks rose, 367 fell and one closed unchanged as the index slipped 0.5%.
Percentage of stocks above their 200-day moving average
The 200-day moving average is a stock's average closing price over its last 200 trading days. When more than half of stocks trade above it, most of the market is in a longer-term uptrend.
As of the October 23, 2026, close, 279 of the 500 S&P 500 stocks with at least 200 days of trading, or 55.8%, were above their 200-day average.
This one counts how many stocks are outperforming the S&P 500 itself. Through October 23, 2026, 217 of the 500 stocks that traded all year, or 43.4%, were ahead of the index's 11.4% gain for the year. The other 283 trailed it.
The gap shows up in the median S&P 500 stock's 2026 return, which runs well behind the index.
New highs vs. new lows
This compares the number of stocks closing at a 52-week high with the number closing at a 52-week low. More highs than lows points to a healthier market.
On October 23, 2026, 16 of the 499 S&P 500 stocks with a full year of trading closed at a 52-week high, and 10 closed at a 52-week low.
What does a narrow market mean?
A narrow market means a few big stocks drive most of the index's gain. As of September 30, 2026, the 10 largest holdings of SPY, an S&P 500 index fund, made up about 39% of the fund, as covered in our S&P 500 guide.
When those giants rally, the index can rise on a day when most of its members fall. The equal-weight version of the index removes that effect, and we break it down in equal weight vs. cap weight.
A narrow market isn't automatically a bear market, a debate we covered in narrow breadth and bear markets.
What does market breadth look like in 2026?
The clearest split came at the index's record close of 7,818.93 on October 6, 2026. That day, only 46.6% of S&P 500 stocks were above their 200-day average, down from 73.6% on August 13. The advance-decline line for the index's members peaked on August 14, 2026, and stayed below that level through October 23, even as the index set its record.
Does weak market breadth mean stocks will fall?
Not on its own. On March 30, 2026, the share of stocks above their 200-day average fell to 42.9% as the S&P 500 closed at the low of a 9.1% drop from its January 27 high. The index then went on to set a string of records.
The share hit its 2026 low of 40.4% on September 30, when the index sat just 1.9% below its record close at the time.
Breadth describes how a rally is built, not where it goes next. For one strategist's take on what it means for stock pickers, see breadth and stock pickers.
Past patterns don't predict future returns.
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Frequently asked questions
What is market breadth?
Market breadth measures how many stocks take part in a market move. Broad breadth means most stocks are rising with the index. Narrow breadth means a few large stocks are doing most of the lifting.
What is the advance-decline line?
It's a running total of the number of stocks that rose each day minus the number that fell. A rising line means more stocks are advancing than declining over time.
What does a narrow market mean?
It means a few big stocks drive most of the index's gain while many others lag. Because the S&P 500 is weighted by market value, its largest companies can lift it even when most members fall.
How many S&P 500 stocks are beating the index in 2026?
Through the October 23, 2026, close, 217 of the 500 stocks that traded all year, or 43.4%, were ahead of the S&P 500's 11.4% price gain for the year.
Is weak breadth a bad sign for stocks?
Not on its own. In 2026, the share of S&P 500 stocks above their 200-day average fell to 42.9% on March 30, and the index went on to set records. Past patterns don't predict future returns.
How is breadth different from the equal-weight S&P 500?
Breadth counts how many stocks are rising or beating the index. The equal-weight S&P 500 is a separate index that gives every company the same weight, so its return reflects the average stock.
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