The higher the index, the more expensive A shares are relative to H shares (the higher the premium); Conversely, the lower the index, the cheaper A shares are relative to H shares. An index higher than 100 means that A shares have a premium over H shares, and the higher the index, the higher the premium. AH share premium, as far as individual stocks are concerned, is the price of the same listed company in the A-share and H-share markets multiplied by 100%. On July 9, 2007, Hong Kong Hang Seng Index Service Company released the Hang Seng AH Share Premium Index, and calculated the weighted average premium (or discount) of A shares relative to H shares according to the circulating market value of A shares and H shares included in the index.

AH share premium refers to a listed company that holds both A shares and H shares. After the exchange rate conversion, the share price in the A-share market is higher than that in the H-share market, that is, the premium of AH shares. This situation is quite common, and only a few companies show the opposite situation. For example, 60 1398 China Industrial and Commercial Bank, 60 1628 China Life Insurance, 600036 China Merchants Bank, etc. , showing that the price of H shares after exchange rate conversion is higher than that of A shares.

What are A shares and H shares? Do you all know? AH shares are short for A shares and H shares, and H+a refers to the company's behavior of issuing A shares and H shares on the mainland Shanghai (or Shenzhen) Stock Exchange and Hong Kong Stock Exchange respectively according to the principle of the same share and the same price. If A shares are issued first, then H shares, or both A shares and H shares are issued, we call it "a+h", that is, ah shares. Then we should see that there are obvious differences between A shares and H shares, and even A shares are much more difficult than H shares. Because an obvious reality is that due to the immaturity of the A-share market, the A-share market is mainly a speculative market, and its share price is significantly higher than that of the H-share market.

Therefore, under normal circumstances, the A-share issue price of the same stock is often higher than that of the H-share market. Faced with this reality, "H+A" is of course the least resistance and the easiest to achieve. Since H shares are issued first and then A shares are issued, the issue price of A shares is obviously higher than the market price of H shares or even H shares. Issuing A shares will only increase the interests of H shareholders, and will not harm the interests of H shareholders. In this way, "H+A" has also been actively supported by H-share shareholders.