Green Indicator... But Is the Market Really Rising?

One of the most common misconceptions in the stock market is assuming that a rising index indicates a broadly positive market, or that a falling index means all stocks are being sold off.

However, an index does not measure the number of advancing or declining stocks; rather, it tracks the price movements of constituent companies weighted by their significance within the index. Consequently, the index may rise sharply while the majority of stocks remain flat or decline, or it may fall due to a single heavy-weight stock, even if trading volume in that stock is limited. …