The Korea Composite Stock Price Index gained 1.2%, as foreigners snapped up local stocks for a sixth straight day.
Traders say the long-term outlook for the won remains positive, despite external uncertainties such as the massive earthquake in Japan earlier this month and surging global oil prices. In contrast, the outlook for the euro remains clouded due to ongoing sovereign debt concerns in Europe.
"There's talk that offshore players are going short on the euro versus the won on the view that the euro has seen its near-term peak," said a foreign bank trader, noting that levels above $1.4000 for the euro look overstretched.
News that Portugal's parliament rejected a new government austerity plan, and a report that Moody's will downgrade the credit ratings of Spanish banks both weighed on the euro. As of 0725 GMT the common currency was at $1.4065, The Wall Street Journal reports.
Traders forecast the dollar to trade between KRW1,110 and KRW1,130 Friday, with levels beyond that range seen as potential triggers of central bank intervention.
Most treasury bonds rose mildly, with sentiment helped by continued foreign buying in futures.
Trade over the next few sessions is expected to remain rangebound amid conflicting leads.
"The supply and demand conditions aren't so bad, as investors who had shorted aggressively on local bonds are still in the process of unwinding those positions in the wake of the massive quake and nuclear (crisis) in Japan," a local securities firm trader said.
Traders, however, don't expect any active bond-buying, given the nation's still-solid economic fundamentals and the Bank of Korea's tightening stance.
June bond futures lost two ticks.