On the positive side, modern finance needs more and more mathematical tools, especially in financial engineering and pricing of financial products. As far as the postgraduate entrance examination is concerned, mathematics has advantages, which will also make personal achievements more competitive.
However, there are also unfavorable factors, that is, comprehensive economics in the initial examination, financial specialized courses in the second examination, and compulsory courses in mathematics for undergraduates.
If you are an undergraduate majoring in mathematics, you must choose economics or finance.