The shares of PUBG game maker KRAFTON fell as much as 20% on their debut after raising $3.8 billion in South Korea's biggest IPO in over a decade. KRAFTON Founder Chang Byung-gyu's 14% stake was valued at over $3 billion based on the IPO price, Bloomberg said. KRAFTON's stock closed down 8.8% on Tuesday, valuing the company at $19.32 billion.