SEOUL, South Korea — South Korea's two memory chip giants just posted the most profitable quarters in the country's corporate history, yet their shares have been among the hardest hit in the global selloff in artificial intelligence stocks. For investors weighing Samsung Electronics against SK Hynix, the question is less about which company is making more money and more about which one carries more risk if the AI boom cools.

Record profits, falling shares

Both companies are earning at an unprecedented pace. Samsung Electronics' third-quarter operating profit reached 107.4 trillion won, nearly eight times higher than last year, as revenue increased 127% to 195 trillion won. It became the first South Korean company to surpass 100 trillion won in quarterly operating profit.

SK Hynix was even more profitable relative to its size. The company recorded 104.6 trillion won in revenue and 83.3 trillion won in operating profit in the third quarter, an operating margin of 80%. That margin was the second-highest among global tech giants after Micron's 80.7%.

The stock market has not rewarded either. As of the close on Oct. 23, Samsung and SK Hynix shares had declined 36%........

© International Business Times