What are the trading rules of corporate bonds? Why did I buy listed bonds and get so much more money than when I entrusted them?

Corporate bonds are traded at net price and settled at full price.

Net-price transaction refers to the transaction mode in which bonds are traded at a price excluding accrued interest due to natural growth. Under the net bond trading mode, investors declare and trade at the net price, but the settlement price is still calculated at the full price, that is, the sum of the transaction price and the accrued interest amount is taken as the settlement price.

Accrued interest = face value × coupon rate ÷365 days × interest-bearing days, which refers to the actual calendar days from the value date to the trading day.

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