Korean retail investors’ aggressive leveraged bets on the market’s two dominant AI/Semi names - Samsung Electronics and SK Hynix - are now colliding with a sharp KOSPI correction, triggering the largest wave of forced stock sales in years and raising the specter of a self-reinforcing liquidation spiral.
At its peak last week, the benchmark KOSPI index was up 100% for 2026, rivaling the Nasdaq 100 Index’s 102% surge in 1999 - right before the bubble burst...
Last week we warned, as levered bets soared to record highs... that 'the signal is clear: the cash buffer eroding while active leverage refuses to unwind'.
And the concentration was extremely clear with 'new lows' dominating even as KOSPI hit record-er and record-er highs...
Driven purely by retail momentum chasers, as foreigners were fleeing...
We specifically made the point that the rise of leveraged exchange-traded funds, designed to magnify daily moves, may further intensify a reversal.
Fast forward a week - and sprinkle in some vicious moves in the Korean index (down 17% from the highs in a week) - and those warnings have now punched Korean retail investors in the mouth.
As The Korea Times reports, South Korean investors are facing massive forced liquidations and margin loans come due.
Aggregated over the last few trading sessions, the figure approached ~300 billion won (~$197 million) - the largest such reading in recent memory.
The ratio of forced sales to outstanding margin loans hit 9.1% on that Friday, the highest of the year.
These sales occur mechanically: investors who borrowed from brokerages (typically putting up 30–40% equity) must settle by T+2.
When equity falls below maintenance levels, brokerages automatically sell at the opening call auction - often locking in losses and adding downward pressure that can trigger further margin calls.
“The biggest risk during a sharp market decline is not the drop in prices itself, but forced liquidation,” said Kim Seok-hwan, an analyst at Mirae Asset Securities.
“Investors are advised to reduce leverage, hold more cash and focus on high-quality assets.”
And it is far from over as margin lending balances remain near record highs.
According to the Korea Financial Investment Association, outstanding margin loans climbed to a record 38 trillion won on May 29. Although the balance eased to 37.8 trillion won as of Monday, it remained at an elevated level.
“It is estimated that much of the recently increased margin financing entered the market when KOSPI was trading in the 8,200-8,400 range,” said Noh Dong-gil, an analyst at Shinhan Securities.
“Investors often begin trimming positions voluntarily once losses approach 15 percent, while the risk of forced selling rises significantly around the 20 percent loss level.”
This unwind is the direct consequence of retail investors aggressively piling into Samsung Electronics and SK Hynix using both traditional margin debt and the new wave of single-stock leveraged ETFs launched in late May 2026.
What began as a retail-driven, leverage-fueled melt-up concentrated in two AI stocks is transitioning into a classic de-leveraging event.
The new single-stock 2x ETFs and record margin debt have amplified both the upside and now the downside.
Foreign outflows have provided the fundamental counter-pressure, while mechanical forced sales are adding the accelerant.
Retail leverage that felt like genius in May is now being stress-tested in real time - with the Korean market’s extreme concentration making the moves especially violent.