S&P500 dropped -15.8pts after US President Donald Trump announced that he may consider de-listing Chinese firms from US markets.
Trump Considers Delisting Chinese firms from U.S. markets - Reuters
https://www.reuters.com/article/us-usa-trade-china-limits/trump-considers-delisting-chinese-firms-from-us-stock-markets-source-idUSKBN1WC1VP
Do overall Chinese stocks listed on US markets have impact on investor sentiment or do US companies have close business relationships with China economy and companies?
Whichever reasons may be, above chart shows that weakening of Chinese listed US Companies, is definitely a not a good thing for US markets.