Posco (PKX) surged 5.61% in Thursday's intraday trading, as investors reacted positively to robust quarterly results from its key subsidiaries Posco Future M and Posco International.

Posco Future M, a battery material and chemical unit, swung to a net income of 23.14 billion won in the second quarter, reversing a year-ago loss, and saw its own shares rise 8%. Meanwhile, Posco International posted a 166% jump in net income to 238.4 billion won on an 18% increase in sales, driven by strong trading and energy operations.

The combined earnings beats underscore the diversified strength of the Posco group beyond traditional steelmaking, fueling optimism about the parent company's overall growth trajectory.