Time is a very important concept in investment and financial management. Short-term usually refers to less than one year, medium-term is three to five years, and more than five years is long-term investment. Long-term holding is very important for fund investment. If investors buy and sell frequently in order to obtain the spread income of fund net value, it will greatly increase the cost of subscription and redemption, and actually damage their investment income. According to different fund companies, the transaction cost of a fund's subscription and redemption is generally around 1.5% to 2.0%, which is much higher than the transaction cost of stocks. More importantly, the investment mode of the fund portfolio will generally make the short-term income of the fund worse than that of the stock, but it will enable the fund to obtain sustained and stable income for a long time. Relevant statistics prove that the stock price has a historical trend of long-term continuous rise, which is also an important basis for the fund's long-term investment to be profitable. On this basis, the fund manager can also adjust the investment portfolio and investment strategy according to the economic development cycle and market changes, so as to strive for higher-than-average returns for investors. How to monitor the funds you invest in at an appropriate frequency? In this regard, the market has no unified proposal. Investors can check the profit and loss of the fund once a week according to their own schedule, which will help investors have a comprehensive understanding of the performance of the fund. If time is tight, you can also comprehensively evaluate your financial situation, investment objectives and the performance of holding funds in a long time interval. Only when the fund has undergone substantial changes, investors should make a decision to change their operating strategies.