The first-line and second-line blue chips mentioned in the stock market are relative, and there is no clear definition, and what some people think of as first-line blue chips is second-line in the eyes of others. Generally speaking, the recognized first-line blue chips refer to stocks with stable performance, large liquidity and large total share capital, that is, stocks with greater weight.

For example, the first-line blue chips mentioned in the Shanghai and Shenzhen stock markets usually refer to: China Petrochemical, China Unicom, baoshan iron & steel, China Merchants Bank, Yangtze Power, Huaneng International and other aircraft carrier-level companies with huge market value, excellent performance and relatively monopoly position in the same industry in China.

Generally speaking, the secondary blue-chip stocks in the A-share market refer to the index stocks or non-index stocks whose total share capital and circulating share capital are slightly less than those of the primary blue-chip stocks, but they are also large, with relatively large market value, relatively large scale and excellent performance, which are increasing every year, such as Shanghai Automobile, Wuliangye and ZTE. In fact, these companies are also well-known leading enterprises in the industry (if viewed from the industry alone, they are the first-line blue chips in their respective industries).