Compound interest, also known as profit rolling profit, is actually a model of bank deposits. For example, we have a three-year deposit and set up an automatic rolling deposit. When the deposit expires, the principal and interest are the sum of the deposits, and the future interest is calculated according to the new deposit conditions and interest rate. If profit rolling is taken as a form, it is our investment reinvestment. This practice is really common in some wealth management products, such as "dividend reinvestment". Dividends or earnings of comparative financial products are used to buy back financial products.

As for the fixed investment of the fund, it is simply a fixed investment fund on a regular basis. The logic behind it is that this kind of operation will avoid certain risks and is a risk control means for institutional investment cultivation. Some people say that if the fund has a long time span, it will definitely have benefits. I think the profit of this operation will completely follow the market. Looking back at the historical trend of the market, the long span of ten or twenty years will definitely pay off. Compound interest is terrible, but it should not escape the rise of inflation. Low risk and low return. The subscription method of the Fund is calculated according to the net value.

Suppose you buy the same fund, regardless of the transaction cost, one fund 1 yuan. On the first day, I bought net value 1 yuan, and 80 yuan bought 80 yuan. The net purchase value on the second day is 0.880 yuan 100 copies. When I bought it on the third day, the net value was. 1.280 yuan bought 67 copies ... and so on, the purchase of funds is related to the net value of funds, and the net value of funds is largely related to its varieties. So, if you buy a fund with declining net worth, you may lose money. The return of the fund is not a comparison between the final valuation of our fund and the principal of our investment. For example, one day, the fund rose by two percentage points, and the next day it fell by two percentage points. These fluctuations are actually only changes in valuation, not real gains or losses.

Only after we sell the fund can we invest in 80 yuan every day. In fact, in order to achieve real returns, time is uncertain. Due to the volatility of the stock market, the advantage of fixed investment is to get stocks (chips) at low points, get good profits at high points, and sell them at high points or high points. This is the way to realize income. Otherwise, when the stock market falls back and sells at a low point, it is likely to lose money. Compared with investment, there will be corresponding return loss.