This paper explores the impact of investor sentiment on financial markets in China by taking the quantile causality test. We find that government bond markets, gold markets, and foreign exchange markets are affected by stock investor sentiment, except for in the corporate bond market. In extreme situations, such as excessively optimistic or pessimistic sentiment, these markets will become more vulnerable to suffering from drastic fluctuations. On the contrary, the market return in government bonds, corporate bonds, and foreign exchange also has an influence on stock investor sentiment. Moreover, these links show various asymmetry due to the heterogeneity of different financial markets. Our results are consistent with the noise trader model, which shows the impact of investor sentiment on market returns. Hence, the authorities can sustain the stabilization of financial markets by reducing information asymmetry, guiding the rational sentiment of investors, and increasing effective regulations.Especially in certain extreme pessimistic situations, sentiment in the stock market can lead to drastic fluctuations in other financial markets [15,16], and the authorities cannot maintain market stability and continuity of development. In turn, the performance of these markets is also a remarkable barometer that leads stock investor sentiment to change [17]. Through information in different market environments, external shocks, not only make asset price fluctuate, but also result in stock investors overreacting, and this affects their investment expectations [18]. This bidirectional transmission is regarded as an important factor for the linkage among major financial markets [19]. Hence, investor sentiment plays an important role in the formation of financial market effectiveness. If investor sentiment cannot be reasonably guided, it will be difficult to suppress irrational trading and speculative bubbles and improve market efficiency.Compared with stock markets in developed countries, individual investors account for a large proportion of Chinese stock investors, which makes the whole market more emotional [20]. With a lack of social responsibility and an awareness of sustaining market efficiency, the individual Chinese investor has an underdeveloped investment education and, thus, they often show irrational investment behavior [21]. Hence, market fluctuation frequently happens, and it is difficult for investor sentiment to be properly guided. Not only do investors make irrational trades in the stock market, but they are also more likely to carry their emotions to other markets [22]. If investor sentiment in the stock market spreads to other markets and causes unexpected fluctuations in China, the pricing and operating efficiency of many financial markets will be damaged. As well as the stock market, the gold, bond, and foreign exchange markets are all financial markets with a large scale in China. If such emotional contagion exists in China, investors who excessively ignore the fundamentals will find it difficult to form th...
