apart from those related directly to the original 30 (as with spin-offs or Mergers and acquisitions) and prohibited the sale of assets except when a stock eliminated dividends or was at risk of de-listing from the stock exchange. Unlike later index funds that are usually cap weighted, with greater proportional holdings in larger companies, LEXCX is share weighted: "holding the same number of shares in each company regardless of price." An evaluation by U.S. News & World Report found the fund was passively managed: "for all intents and purposes, this fund's portfolio is on autopilot." The theory underlying passive management, the efficient-market hypothesis, was developed at the Chicago Graduate School of Business in the 1960s. During this same period, researchers first began to discuss the concept of an "unmanaged investment company." In 1969, Arthur Lipper III became the first to try to turn theory into practice by petitioning the Securities and Exchange Commission to create a fund tracking the 30 stocks Dow Industrial Average. According to Lipper, the SEC did not respond. The first index funds were launched in the early 1970s, by American National Bank in Chicago, Batterymarch, and Wells Fargo; they were available only to large pension plans. The first index fund for individual investors was launched in 1976. The Vanguard First Index Investment Fund (now the Vanguard 500 Index Fund) was the brainchild of John (Jack) Bogle. Investment in passive strategies Research conducted by the World Pensions Council (WPC) suggests that 15% to 20% of overall assets held by large pension funds and national social security funds are invested in various forms of passive funds- as opposed to the more traditional actively managed mandates which still constitute the largest share of institutional investments. The proportion invested in passive funds varies widely across jurisdictions and fund type. The relative appeal of passive funds such as ETFs and other index-replicating investment vehicles has grown rapidly for various reasons ranging from disappointment with underperforming actively managed mandates to the broader tendency towards cost reduction across public services and social benefits that followed the 2008-2012 Great Recession. Public-sector pensions and national reserve funds have been among the early adopters of passive management strategies. At the Federal Reserve Bank of St. Louis, YiLi Chien, Senior Economist wrote about return-chasing behavior. The average equity mutual fund investor tends to buy MUTUAL FUNDS with high past returns and sell otherwise. Buying MUTUAL FUNDS with