Seoul apartment prices rise for an 85th week while the Gangnam districts turn negative

Seoul apartment prices gained 0.13% in the week to 21 September, an 85th consecutive rise that equals the record, even as Gangnam fell 0.42%.

Apartment sale prices in Seoul rose 0.13% in the week to 21 September 2026, according to the weekly index published by the Korea Real Estate Board on 24 September. It was the 85th consecutive weekly increase, equalling the longest unbroken run the series has recorded. The gain was slower than the previous week's 0.16%, and the deceleration has a clear source: three of the city's most expensive districts are now falling.

Gangnam-gu recorded minus 0.42% on the week, Seocho-gu minus 0.37% and Songpa-gu minus 0.14%. At the other end, Seodaemun-gu rose 0.44%, Dongdaemun-gu and Seongbuk-gu 0.39% each, Nowon-gu 0.37% and Jungnang-gu 0.36%.

A record streak that is changing shape

Eighty-five weeks of uninterrupted gains is the headline, but the composition underneath it has inverted. A streak sustained by the prime south of the river has become a streak sustained by the mid-priced north and east. The three districts that led Korean price growth through the last cycle are now the only ones subtracting from the city total.

That pattern is familiar from other tightly regulated capitals. When lending caps and designated speculation zones bite hardest at the top of the market, transaction activity migrates down the price ladder rather than stopping, and the index keeps rising on a different set of postcodes. The streak continues; the market driving it is not the same market.

Gyeonggi is accelerating as Seoul slows

The province surrounding Seoul moved the other way. Gyeonggi apartment prices rose 0.23% on the week, up from 0.18% the week before, so the wider capital region is gaining momentum precisely as the city at its centre loses it. For a buyer priced out of Seoul, the commuter belt is where the bid is going, and it is the clearest evidence that the cooling in Gangnam is a redistribution of demand rather than its disappearance.

Rental deposits are still tightening

The jeonse index, which tracks the large refundable deposits that dominate Korean leasing, rose 0.19% in Seoul, up from 0.17% a week earlier. Gyeonggi jeonse matched its previous reading at 0.15%. Rising jeonse alongside softening prime sale prices is a distinctive Korean signal: households that cannot or will not buy stay in the deposit market instead, pushing up the cost of the lease rather than the purchase.

What our own data can and cannot show

One limitation belongs in the open. The Board's own bulletin list confirms the release's date and title on a server-rendered page, but the figures themselves sit in an attachment our reading route cannot open, so every number above is one that two independent Korean quality outlets published identically; figures carried by only one were left out.

The weekly index is also not the source behind Glopra's own price level. Our Seoul row carries an average apartment price of 1,197,052 US dollars per unit for August 2026, taken from the monthly housing survey run by KB Kookmin Bank, a different publisher measuring a different thing at a different frequency. We store no national South Korean average at all, and the reason is published on the row: the official national price levels are not available on a page we can read, and we do not substitute new-build presale figures for the existing stock. Rental income in South Korea is not taxed at the rates that apply in most of the markets we cover, which changes the net arithmetic for a foreign buyer considerably. The next weekly reading falls in the Chuseok holiday period, so its timing may slip.

Sources: Korea Real Estate Board, Weekly Apartment Price Trends as of 21 September 2026, published 24 September 2026 https://www.reb.or.kr/reb/na/ntt/selectNttList.do?mi=9565&bbsId=1154; MoneyToday, 24 September 2026 https://www.mt.co.kr/estate/2026/09/24/2026092410214197484; Newsworks, 24 September 2026 https://www.newsworks.co.kr/news/articleView.html?idxno=854815

Market data: Seoul · South Korea