The number of stocks advancing and declining can give a good read-through on the health of the underlying market; for example, at MM, we often refer to “broad-based” buying. The difference between the advances & declines is usually referred to as the market breadth with the running cumulative total of daily breadth known as the Daily Advance-Decline Line, an important read on the market’s underlying health as it provides another tool to quantify the movements of the market other than looking at the price levels of indices. We often read about how the “Magnificent Seven” are driving US indices on their own, but the below chart illustrates the internals are still firm, although, of course, from a points perspective, they are aiding performance.
