South Korean technology giant Samsung Electronics has reported a record operating profit of $62 billion for the April-June quarter. The earnings were reported Thursday, a day after crosstown rival SK Hynix also reported record earnings. The world’s two largest memory chipmakers are riding a global artificial intelligence boom. Despite their soaring profits, the companies’ shares have fallen sharply this week in South Korea’s volatile stock market, where retail investors often drive sharp swings in share prices. Concerns have grown over their plans to put massive funds into increasing their manufacturing capacity and the prospects of intensifying competition from China.