To answer your first question, the source of income of fund management companies is to collect management fees. The larger the management scale, the more income. Fund management companies disperse risks by selling funds with concentrated fund shares and investing in various securities. For investors, buy fund shares, enjoy the benefits and take risks. The second problem is that investment is risky. What kind of investment may have a fixed income? Every investment product will face systemic risks, which is inevitable. Third, the fund had better not speculate in the short term, because the short-term speculation of the fund needs to pay the subscription fee and redemption fee. Fund is a kind of long-term investment, many a mickle makes a muckle, and it gains an average rate of return with the market. In addition, the fund interest rate is fixed. In a word, a fund is a fund company that invests securities (stocks, bonds and derivatives) for investors with investors' money and collects management fees from them.