SINGAPORE -- Asia-Pacific Stock markets slid Friday afternoon after U.S. President Donald Trump said he tested positive for COVID-19, spurring investors to avoid risk ahead of the Nov. 3 presidential election.
Japan's benchmark Nikkei Stock Average declined 233 points at one point in the afternoon trading session, dipping under 23,000 points for the first time since Sept. 9 before closing at 23,029. The market resumed trading Friday after a full-day system outage the day before.
Among major stocks that fell after Trump's announcement via Twitter were Sony and Toyota Motor, which both have a strong U.S. presence. Sony shares ended 3.5% down, while Toyota fell 0.6%. Shares in key iPhone supplier Murata Manufacturing also dropped in afternoon trading, ending 0.3% lower.
Other major regional stock markets also declined. Singapore's Straits Times Index and Thailand's SET index both fell around 1% at one time in the afternoon. Among those hit were financial institutions. Thailand's Kashikonbank and Bangkok Bank saw their shares drop soon after the news broke from the U.S.
Australia's All Ordinaries index, meanwhile, fell 1.4%.
Falling oil prices were another factor pressuring some of Asia's energy stocks. Thailand's PTT Exploration and Production dropped as much as about 5% at one point, while Singapore conglomerate Keppel Corp., which engages in offshore oil rig building, declined more than 2%.
South Korea, China, Taiwan, Hong Kong and India are all on public holiday Friday, meaning it will not be known until next week how some of Asia's biggest stocks, such as Samsung Electronics and Taiwan Semiconductor Manufacturing, will react to the news about the U.S. president's infection.
Elsewhere, Malaysia's benchmark KLCI outperformed regional peers on Friday due to strong gains by health care related stocks, including rubber glove makers Hartalega Holdings and Top Glove.
Trump revealed his infection on Twitter around 2 p.m. Tokyo time and 1 p.m. in Singapore and Hong Kong. "Tonight, @FLOTUS and I tested positive for COVID-19," he said, referring to his wife Melania. "We will begin our quarantine and recovery process immediately. We will get through this TOGETHER!"
U.S. equity futures dropped sharply after his tweet, with one tied to the Dow Jones Industrial Average plummeting more than 600 points. The fall in U.S. futures also affected sentiment in Asian markets.
Concerns also surfaced in foreign exchange markets, pushing the Japanese yen up against the U.S. dollar. The yen appreciated to around 105.00 against the greenback after Trump's tweet, from around 105.60 previously.
"Asian markets were marked lower as the uncertainty caused by the Trump COVID-19 announcement caused an immediate flight to haven assets," said Jeffrey Halley, senior market analyst at OANDA.
With respect to the market outlook, he said that "much will depend on whether COVID-19 has been contained to the White House and its staff, or whether it is now moving amongst the wider governmental leadership circles."
"In such a case we will see a continued exodus to risk-hedging assets. The seriousness of President Trump's condition will also be closely watched for the same reasons."
Meanwhile, Stephen Innes, chief global market strategist at Axi, told Nikkei Asia that Friday's sell-off in Asian markets was "due to the market pricing in a Biden presidency", referring to Democratic challenger Joe Biden, who is expected to implement increases in corporate taxes if he wins the election.
The first lady later tweeted that she and the president were "feeling good." Still, the Republican Trump's quarantine casts uncertainties over the ongoing presidential election campaign. It is possible he will miss some of his rallies, while the next debate with Biden could be affected. Such questions could cause more volatility in markets in the coming weeks.