What was mentioned earlier was the difference at the macro level.

In terms of market structure, going long in U.S. stocks relies on the U.S.'s control over global capital. U.S. stocks, the U.S. dollar, and U.S. Treasury bonds are all in the same boat, so it's necessary to buy U.S. stocks to enhance the attractiveness of the dollar in order to protect U.S. bonds. This is the prerequisite for dominance. On the other hand, short selling relies on insider trading, conspiracy theories, information warfare, and fundamental research, which also means it's very difficult to short U.S. stocks.

Going long in Hong Kong and A-shares relies on institutional clustering. There are many institutions in A-shares, so the clustering is tight, while there are fewer domestic capital institutions in Hong Kong stocks. Therefore, under the condition of low market control, the strength of going long will be much smaller. This is the prerequisite for dominance. In Hong Kong stocks, both going long and shorting rely more on "mob-like" trading. When the market lacks a clear trading direction, quantitative funds will harvest by creating intraday volatility, which also suppresses trend formation.