I used to check the percent of stocks trading above the 20,50 and 200 day moving averages on the website Barchart.com
I noticed a tendency for stocks to decline a bit when the percentage of stocks trading above the 20 day moving average approached 80 percent.
The technical analyst folks would describe such a situation in the market as overbought or oversubscribed.
Likewise, when the percentage of stocks trading below the 20 day moving average reached 80 percent the general market would rally.
The technical analyst folks would describe such a situation in the market as oversold or undersubscribed.
Many decades when the legendary JP Morgan was moving and shaking on Wall Street, a financial reporter asked him what the market would do today.
JP answered, "it will fluctuate."
That tendency for fluctuation, at least short term, is what traders attempt to profit on.
Traders, like gamblers, like action.