Suppose there’s someone called Xiao Gu who works the evening shift at a pharmacy by the entrance to his residential complex. In the evenings, quite a few people come by to buy cold medicine and bandages. He’s busy handling payments and finding products, so he rarely keeps an eye on the market.

On November 6, $PORTO closed at 0.390. He took a look before leaving work and bought some at that closing price.

On November 7, it opened at 0.390, exactly the previous day’s closing price. The high that day was 0.439, which was 12.56% above his cost of 0.390. He was at work then, hadn’t placed a sell order, and didn’t catch that price.

After reaching its high, the price fell. The low that day was 0.372, which was 4.62% below his cost of 0.390. It closed at 0.373, down 4.36% from the opening price of 0.390. From the high of 0.439 to the close of 0.373, it fell 15.03%.

Later, Xiao Gu told a coworker who was on shift with him: “I bought at 0.390 on the 6th. On the 7th, it reached a high of 0.439, which was 12.56% above my cost. I was at work and didn’t catch it, and I hadn’t placed a sell order either. It closed at 0.373, which was 4.36% below my cost. From the high to the close, it fell 15.03%.

“If you hadn’t seen that high during the day, hadn’t placed a sell order in advance, and the closing price was 4.36% below your cost, would you feel you should keep holding, or place a sell order in advance?”