South Korean stocks plunged on Friday, with the Kospi closing below 7,500 points after briefly touching the 8,000-point threshold earlier in the day. Investors rushed to book profits after the historic milestone was achieved.

The Kospi had opened slightly lower in the day but quickly rebounded, briefly surpassing the 8,000 mark before sharply reversing. The index later plunged to as low as 7,371.68, triggering a sell-side sidecar around 1:30pm, which was the first such measure since April 2.

The Korea Composite Stock Price Index or Kospi decreased by 488.23 points, or 6.1%, to end at 7,493.18. The Kosdaq also declined by 61.27 points, or 5.1%, to close at 1,129.82.

In economic news, South Korea's export prices rose 40.8% year-over-year in April, while import prices gained 20.2%, according to preliminary data from the Bank of Korea released on Friday.

On a month-on-month basis, the export price index increased 7.1%, while the import price index declined 2.3%, the data showed.

The net barter terms of trade index gained 14.3% on-year during the month.

In corporate news, Hana Financial Group's (KRX:086790) Hana Bank will acquire 6.55% of crypto exchange operator Dunamu for 1.003 trillion won, the financial group said in a Friday filing with the Korea Exchange.

The bank will acquire 2.28 million shares in the target on June 15, which are currently held by Kakao (KRX:035720) subsidiary Kakao Investment. The transaction will be settled in cash, the filing said.

Shares of Hana Financial Group fell nearly 6% at market close, while those of Kakao declined over 4%.