Why is there a change in the profit and loss of a position on the pre-IPO market day

During the pre-IPO market trading period, the market value and profit/loss of holding positions will be calculated based on the latest pre-IPO market price for reference only.
The system will switch back to the latest exchange price (IPO issue price) after 24:00 on the pre-IPO trading day, which results in changes in market value and profit and loss, but it will not affect your actual assets and income.