The algorithm of fund companies is different. The rise and fall are calculated according to the previous day. A 5% increase in the net value of 1 is 1.05, and when you fall by 0.5%, the net value is 0.9975. So if it falls fast and rises slowly, the fund company will make a steady profit, whether you lose or win. The stock market is like a casino, and fund companies are like professional gamblers.