Seoul: The benchmark rate for banks' mortgage rates increased for a fourth consecutive month in December, data showed Thursday. COFIX, or the Cost of Funds Index, a benchmark lending rate for mortgage loans, rose to 2.89 percent last month, marking an increase of 0.08 percentage point from the previous month, according to the data from the Korea Federation of Banks.

According to Yonhap News Agency, COFIX is calculated based on the funding costs of eight domestic banks in South Korea, including Nonghyup Bank, Shinhan Bank, Woori Bank, and Citibank Korea. This consistent rise in the benchmark rate indicates a trend that could impact mortgage borrowers in the coming months.

Earlier in the day, the Bank of Korea (BOK) maintained its benchmark interest rate at 2.5 percent, emphasizing the need to safeguard financial stability amid a weakened local currency. This decision marks the fifth consecutive month the BOK has chosen to keep the rate unchanged.

The central bank has previously reduced the key rate by a cumulative 100 basis points to 2.5 percent since October 2024 to bolster economic growth. This monetary policy stance reflects the BOK's efforts to balance economic support with financial stability concerns.