Asian markets edged up Tuesday but dealers remained cautious as the optimism over Britain's EU membership that drove a global rally faded, with the knife-edge referendum just days away.
With a series of polls putting the "Leave" and "Remain" camps neck and neck ahead of Thursday's poll, two of the world's investment titans, Li Ka-shing and George Soros, warned an exit vote would spell economic doom for Britain.
While stock traders built on the past two sessions' gains, the pound slipped back slightly after enjoying its best single-day gain since the dark days of the global financial crisis in 2008.
"The markets have a myopic focus on one thing: the UK referendum vote," Chris Weston, chief market strategist at IG Ltd. in Melbourne, told Bloomberg News.
"All the euphoria of yesterday has seemingly abated and we hit the refresh button. We almost need to take this week one day at a time, such is the nervousness around trading."
Dealers are also awaiting testimony on the US economy by Federal Reserve boss Janet Yellen from Tuesday.
In early trade Hong Kong added 0.6 percent, Shanghai gained 0.8 percent and Tokyo was up 0.5 percent by the break.
Sydney put on 0.4 percent and Singapore 0.2 percent while there were also healthy advances in Taipei, Manila and Jakarta.
The pound edged down to $1.4663 from $1.4675. At one point it jumped 2.4 percent Monday to a three-week high of $1.4708.
- 'Pound faces 20 pct dive' -
Li and Soros were the latest in a succession of business and political leaders to have thrown their weight behind the campaign for Britain to stay in the economic bloc.
Writing in the Guardian, Soros -- who made a billion pounds out of Britain's collapse from the Exchange Rate Mechanism in 1992 that became know as Black Wednesday -- warned of a Black Friday if the country leaves.
"Sterling is almost certain to fall steeply and quickly if leave wins the referendum," Soros wrote.
"I would expect this devaluation to be bigger and also more disruptive than the 15 percent devaluation that occurred in September 1992."
He warned Britain would be in a worse position this time as the Bank of England already has interest rates at 0.5 percent, while they were at 10 percent in 1992.
Separately, Li -- one of Asia's richest men who has huge investments in Britain from power to telecoms -- said an exit would hurt the entire continent.
"If Brexit happens, it will be detrimental to the UK and it will have a negative impact to the whole of Europe," he said in his first interview with international media since 2012.
"Of course I hope that the UK doesn't leave the EU."
- Key figures around 0230 GMT -
Tokyo - Nikkei 225: UP 0.5 percent at 16,046.62 (break)
Shanghai - Composite: UP 0.8 percent at 2,911.75
Hong Kong - Hang Seng: UP 0.6 percent at 20,631.54
Euro/dollar: UP at $1.1334 from $1.1311 late Monday
Pound/dollar: DOWN at $1.4663 from $1.4675
Dollar/yen: DOWN at 103.90 yen from 103.93 yen
New York - DOW: UP 0.7 percent at 17,804.87 (close)
London - FTSE 100: UP 3.0 percent at 6,204.00 (close)