U.S. stock index futures were broadly lower on August 18, with Nasdaq futures down 1.16%, S&P 500 futures down 0.55%, and Dow futures down 0.16%. According to Sina Finance, the 30-year U.S. Treasury yield rose to 5.3242%, the highest level since 2007.

Pre-market trading was weak across memory chip makers and major technology stocks. SK Hynix, SanDisk, and Western Digital fell more than 5%, while Seagate dropped 5%; Micron Technology and Intel fell more than 3%. Nvidia fell more than 2%, SpaceX and Tesla fell more than 1%, and Alphabet, Amazon, and Meta also declined, while Microsoft and Apple edged higher.

Among popular Chinese stocks, iQIYI fell more than 9% after reporting an adjusted net loss of 210 million yuan in the second quarter, compared with a profit a year earlier. Hesai Technology fell more than 7%, NIO and XPeng fell more than 1%, and JD.com, PDD Holdings, and Baidu also declined. Alibaba rose 3.5%, while WeBus extended its strong pre-market rally, up more than 43% and nearly 400% over the past five trading days after announcing a strategic $300 million non-equity financing plan.

According to Sina Finance, Cleveland Fed President Beth M. Hammack said some number of rate hikes may be needed and that she does not want to predict how many or the final rate level. Richmond Fed President Thomas I. Barkin said it remains unclear whether more tightening is needed to reach the inflation target, and that inflation still carries persistent risks.

Goldman Sachs chief economist Jan Hatzius said the chance of a rate hike at the Fed's September meeting is extremely low. The Fed will release minutes of its July policy meeting at 10:00 (UTC+8) on August 20.