An index fund’s rules of construction clearly identify the type of companies suitable for the fund. The most commonly known index fund in the United States, the S&P 500 Index Fund, is based on the rules established by S&P Dow Jones Indices for their S&P 500 Index. Equity index funds would include groups of stocks with similar characteristics such as the size, value, profitability and/or the geographic location of the companies.
In Prosper’s case, its Index fund is composed of partner project tokens. In other words, assets that pledge and are monitored to ensure that they operate within planetary load limits.
Index funds are generally considered ideal core portfolio holdings for retirement accounts, such as individual retirement accounts (IRAs) and 401(k) accounts. Legendary investor Warren Buffett has recommended index funds as a haven for savings for the sunset years of life. Rather than picking out individual stocks for investment, he has said, it makes more sense for the average investor to buy all of the S&P 500 companies at the low cost an index fund offers.