Traders work at the New York Stock Exchange in New York, the United States, Aug. 2, 2019. Photo: Xinhua

The gains in Chinese mainland stocks faltered on Wednesday, with the key Shanghai Composite Index shedding 1.22 percent, or 37.91 points, to close at 3,066.89 points. The Shenzhen Component Index and the ChiNext index both posted losses of over 1 percent.

An attack by Iran aimed at US targets in Iraq in retaliation for the US killing of a top Iranian general has apparently created panic among investors. Stocks related to Tesla were arguably among the top performers on Wednesday, alongside gold and defense stocks. The Tesla sector gained 1.57 percent during the day, with over 10 stocks rising by the daily 10 percent limit. 

The continued surge in A shares is likely to help NASDAQ-listed Tesla reap more gains. The US electric vehicle giant soared 3.88 percent to close at $469.06 on Tuesday, rendering Tesla the most valuable US carmaker ever.

Yet the stimulant could not fend off unfavorable news clouding two of the 30 largest stocks forming the Dow Jones Industrial Average. 

CITIC, a Hong Kong-headquartered listed arm of Chinese state-owned conglomerate CITIC Group, announced plans to sell stakes in McDonald's Corp's China operations, a move that creates uncertainty for NYSE-listed McDonald's Corp. 

In another blow, the loss of a Ukraine Boeing-737 plane carrying more than 170 people, which crashed near Tehran on Wednesday shortly after takeoff will again send a danger signal for the US firm which has over the past year been embroiled in public doubts over the safety of its aircraft.

Worries over the two Dow 30 firms could highly likely subdue US stocks in a selloff mode that might be spread to markets across the globe.