South Korea's exports grew more than expected in May at the strongest annual rate in over four decades, as a global boom in AI investment drove chip sales to a record, swelling optimism on the trade-reliant economy and its world-beating stock rally. Exports from Asia's fourth-largest economy, a bellwether for global trade, rose 53.2% from a year earlier to a record high of $87.75 billion, preliminary trade data showed on Monday, exceeding the median 48.4% increase forecast in a Reuters poll. It was the 12th consecutive month of exports growing on a year-on-year basis and the biggest percentage rise since January 1984, bringing a record monthly trade surplus for the country. "It is truly an unprecedented pace, raising market expectations again and again and exceeding them again and again," said Stephen Lee, an economist at Meritz Securities in Seoul. He is forecasting even stronger momentum in the third quarter and export growth of around 50% for the full year.