In short, a local government built an unprofitable Legoland, said local governor threatened not to repay the loans, and now the entire Korean municipal + corporate bond market is at risk.
Source: https://foreignpolicy.com/2022/11/10/legoland-south-korea-bond-market-crisis/
But the fallout is not limited to local government bonds; it impacts the whole of South Korea’s bond market, worth more than $2 trillion. Corporate bonds are considered less safe than local government bonds. If few buyers are brave enough to buy local government bonds under these conditions, even fewer buyers can muster enough courage to buy corporate bonds. One of the safest corporate bonds in South Korea is issued by Korea Electric Power Corp. (KEPCO). The returns for KEPCO’s three-year bond had climbed from 2.184 percent to 5.825 percent since the beginning of this year. But in its latest issuance, the KEPCO three-year bond worth 200 billion won (about $146 million) could not find a buyer.
And
To prevent the credit market from seizing up completely, the South Korean government stepped in by providing a liquidity facility of more than 50 trillion won (about $35 billion). The Bank of Korea also injected 42.5 trillion won (about $31 billion) to stabilize the short-term bond market, and South Korea’s five largest banks also pledged to provide up to 95 trillion won (about $67 billion) in liquidity. There is an absurdist quality to these measures: On the one hand, the Bank of Korea has been aggressively raising the benchmark interest rate to curb inflation by reducing liquidity, but on the other hand, the South Korean government is injecting liquidity to the market to stave off a total economic collapse.