S&P 500 Index and Its Constituent Stocks

Introduction to Standard & Poor’s The S&P 500 Index—short for Standard & Poor’s 500 Index—is a stock market index tracking 500 leading publicly traded companies in the United States. This index is compiled and maintained by Standard & Poor’s (S&P). All companies included in the S&P 500 are listed on major U.S. exchanges, such as the New York Stock Exchange (NYSE) and Nasdaq. Compared with the Dow Jones Industrial Average, the S&P 500 includes a broader set of companies, resulting in greater diversification of risk and a more comprehensive reflection of overall market movements. The S&P 500 Index was first launched by Standard & Poor’s in 1957. Initially, its constituent stocks comprised 425 industrial stocks, 15 railroad stocks, and 60 utility stocks. Starting July 1, 1976, the composition was revised to include 400 industrial stocks, 20 transportation stocks, 40 utility stocks, and 40 financial stocks. The index uses the period from 1941 to 1943 as its base period, assigning a base value of 10. It is calculated using a weighted average method, with the weight assigned according to each stock’s number of shares outstanding, and all calculations are based on the base period.

Behavioral investors aim systematically to profit from investors’ incurable irrationality. It sounds crazy—but it appears to work. June 14, 2005 Russell Fuller, partner at Fuller & Thaler Asset Management in California, observes that “all portfolio managers attempt to identify mispriced securities.” Yet in his research, Fuller goes beyond conventional financial data to probe human psychology. Using psychological insights, he seeks to identify irrational investor behaviors that cause stocks to be either undervalued or overvalued. Fuller’s research collaborator is Richard Thaler, Professor of Economics and Behavioral Science at the University of Chicago Booth School of Business—and one of behavioral finance’s foremost theorists. This discipline has existed in some form since the 1970s (some would argue for centuries). But since the collapse of the technology-stock bubble in 2000, behavioral investing has emerged as a distinct asset management methodology—highlighting just how irrational investor exuberance can be. Admittedly, behavioral investing still has a long way to go before it eclipses modern portfolio theory, which rests partly on the Nobel Prize–winning “efficient market hypothesis” advanced by Harry Markowitz and William Sharpe. The controversial hypothesis holds that markets are efficient because stock prices fully reflect all available information about a stock at any given moment. In direct contrast, behavioral finance argues that markets become highly inefficient—and stocks severely mispriced—whenever investors behave irrationally, as they frequently do. When behavioralists seek undervalued stocks to buy and overvalued stocks to avoid (or short-sell), they appear remarkably similar to value investors. Yet for behavioralists, human psychology—not underlying corporate fundamentals—is the starting point. “The efficient market theory tells us it’s impossible to beat the market,” says Woody Dorsey, president of Market Semiotics, a research firm headquartered in Castleton, Vermont, which applies behavioral methods to forecast markets for approximately 80 institutional clients—primarily large hedge funds. “Behavioral finance says you can.” In 2002, Daniel Kahneman, Professor of Psychology at Princeton University, received the Nobel Prize in Economic Sciences for his pioneering research integrating psychology and economics—greatly enhancing the credibility of Market Semiotics’ approach among investors. In essence, Kahneman posits that human investors are more loss-averse than gain-seeking—contrary to the coolly rational “economic man” assumed by neoclassical economists. Human investors’ decisions depend heavily on how choices are framed, and they assess their own economic well-being not in absolute terms but relative to others. A key principle of Kahneman’s theory directly relates to securities markets: the “endowment effect,” which posits that people assign higher value to things they already own—such as stocks.

Why Is H.B. Fuller (NYSE:FUL) Reshaping Debt Amid S&P 500 Trends?

Oct 11, 2026

H.B. Fuller plans to issue senior unsecured notes to finance its acquisition of AMS, focusing on capital structure optimization and manufacturing efficiency. Meanwhile, shareholders are urging potential divestment of its Building Adhesive Solutions business within the specialty chemicals sector.