(Changes headline, revises market figure in lead, adds analyst,
trader comments in paragraphs 4 to 6, context on king's health)
BANGKOK Oct 10 Thailand's main stock index
tumbled as much as 3.6 percent on Monday and the baht fell to
more than two-month lows, a day after the palace said that
88-year-old King Bhumibol Adulyadej's health was in an unstable
The Stock Exchange of Thailand sank in opening trade
by the most in nearly a month. By 0420 GMT it was down 2.9
The Thai baht fell to as low as 35.065 to the
dollar, down nearly half a percent on the day and its weakest
since July 26. By 0400 GMT it was around 34.99 to the dollar.
"Markets tend to react more out of news from the royal
household, more than news on political upheaval that we've had
in the past," a Singapore-based economist, who declined to be
identified because of the sensitivity of the matter, told
"Over the last few weeks the health updates have been coming
out with more frequency and that's showing up in the currency
and stock market," he added.
A Bangkok-based trader, who also declined to be identified,
told Reuters that the king's health was a concern for domestic
and foreign investors.
Thailand's king, the world's longest reigning monarch, is in
an unstable condition after receiving haemodialysis treatment,
the palace said in a statement late on Sunday. Doctors gave him
some medicine and put him on a ventilator to bring his blood
pressure back to normal, it said.
News about the king is closely monitored in financial
markets in Thailand, where he is widely revered and where he is
seen as arbiter in politics.
The palace had said on Oct. 1 that the king's condition had
improved following a lung infection. He has been treated in
recent months for hydrocephalus, an excessive build-up of fluid
on the brain.
Thailand has weathered more than a decade of unrest
including military coups in 2006 and 2014 and a wave of deadly
bombings in August that killed four Thai tourists and injured
dozens, including foreigners.
(Reporting by Amy Sawitta Lefevre, Pairat Temphairojana, and
Wirat Buranakanokthanasan; Editing by Amy Sawitta Lefevre and