多只港股“入通”后剧烈波动，发生了什么？

Core Viewpoint - The recent inclusion of multiple Hong Kong stocks into the Stock Connect program has led to significant price volatility and increased trading activity, driven by various factors including index adjustments, new capital inflows, speculative trading, and limited share availability [1][2][4]. Group 1: Stock Performance - Several stocks, such as药捷安康-B and佰泽医疗, experienced dramatic price movements after being included in the Stock Connect, with药捷安康-B seeing a peak increase of over 1000% shortly after inclusion, followed by a sharp decline of 53.73% [2][4]. - The average trading volume for these stocks surged significantly post-inclusion, with some stocks experiencing increases in daily trading volume by several times to dozens of times compared to before [3][4]. Group 2: Reasons for Volatility - The adjustment of index constituents has led to passive buying from ETFs tracking these indices, contributing to the volatility of newly included stocks [4][5]. - The inclusion of these stocks has opened up opportunities for mainland investors, resulting in a notable influx of capital into these stocks [5][6]. - Speculative trading has also played a role, particularly in the healthcare sector, where stocks with innovative drug concepts have attracted attention [6][7]. - Many of the stocks included are relatively new to the market, with limited free-floating shares, making them more susceptible to extreme price fluctuations when capital flows in [6][7].