The Bank of Korea (BOK) warns that single-stock leveraged exchange-traded funds (ETFs) linked to Samsung Electronics and SK Hynix could increase risks for the domestic stock market, according to reports citing a written response to a lawmaker. The BOK says the products may worsen existing market concentration in a small number of semiconductor stocks, noting that Samsung and SK hynix together account for more than half of Korea’s stock market by market capitalization and trading value. The central bank also warns that leveraged ETFs could amplify volatility and intensify “one-way” trading flows, as investor money may move quickly into or out of these funds in reaction to changes in market expectations or the chipmakers’ business environment. The warnings are described as rare and are expected to strengthen the momentum behind efforts by financial authorities to tighten investment requirements for high-risk leveraged ETF products. Overall, the BOK frames the issue as a potential feedback loop: concentrated ownership and rapid leveraged flows could make market swings more pronounced and more persistent during periods of rapid sentiment change.