The original ETF boom was about low cost, tax-efficient core index funds. Now single-stock ETFs are upping risk, with leverage getting 'a little carried away.'

South Korea's ruling party has begun reviewing possible curbs on single-stock leveraged exchange-traded funds tied to Samsung Electronics and SK hynix, as regul

South Korean retail investors now drive 70% of the $4.3T market through leveraged ETFs on Samsung and SK Hynix, pushing margin debt to record $39 billion.