The HK50 is the Hang Seng Index in Hong Kong, a market capitalization-weighted index of the largest companies listed on the Hong Kong Stock Exchange. While it is not directly related to the US30 index, developments in the HK50 can still have an impact on US30 index trading, especially as it relates to industrial companies with global operations. Traders should monitor the HK50 for any news or developments that could potentially impact their US30 positions.