The reasons for the serious deviation of CSR's stock price after the merger of China South Locomotive and Rolling Stock Corporation and China CNR are as follows: 1. Market expectations do not match: Investors may have different expectations for the prospects of the company after the merger.

If the market generally takes a negative view of the combined company, the stock price could decline.

This may be because investors are worried that the combined company will encounter difficulties in the integration process, or are skeptical about the profitability of the new company.

2. Integration difficulties: The merged company needs to be integrated, including business integration, resource integration, etc.

If problems arise during the integration process, such as management conflicts, cultural differences, etc., it may affect the company's operating conditions and investor confidence, causing the stock price to fall.

3. Changes in the macroeconomic environment: Changes in the macroeconomic environment may also have an impact on stock prices.

If the overall economic environment is unstable and market sentiment is depressed, it may cause the stock price to deviate.

4. Company financial condition: The financial condition of the merged company may also be a factor that affects the stock price.

If the combined company faces financial difficulties and poor earnings expectations, investors may be cautious about stock price performance.