The actress reportedly made those millions of dollars from her real estate investment in just three years, according to a News1 article. Song Hye Kyo bought a five-story building at the entrance to the Hannam the Hill apartment complex, one of Seoul’s most upscale real estate developments, with a land area of 149.35 pyeong and a building area of 74.61 pyeong, according to statistics from the real estate company Building Road. Song bought in 2021 for approximately $14.6 million USD, or ₯19.5 billion KRW.

The actress paid ₩11.5 billion KRW (about $8.63 million USD) in cash at the time of the purchase, with the remaining amount coming from a bank loan. She purchased the property under her own name.
The land cost each pyeong when Song purchased the property was ₩131 million KRW (about $98,000 USD), but it is currently worth ₩165 million KRW (roughly $124,000 USD). Given that the building was constructed in 1989, the value of the property is mostly determined by the cost of the land. As a result, Song’s building is currently valued at ₩25.5 billion KRW, or roughly $19.2 million USD, on the market—a massive ₩6.00 billion KRW, or roughly $4.50 million USD, more than she paid for it three years ago.