Tokyo’s condo market is showing early signs of cooling after policy tweaks by the Bank of Japan spurred speculation that mortgage burdens may rise, prompting some homebuyers to think twice before purchasing.

The number of existing apartments up for sale in central Tokyo’s popular bay area rose for two straight weeks in January — the first back-to-back increases since April, according to real estate broker Wangan Mansion Kakaku Navi. Secondhand apartments for sale in the city’s 23 wards jumped more than 30% in January from a year earlier, the most in 10 years, Tokyo Kantei figures show.

It’s way too soon to conclude that the figures spell doom for the Japanese capital’s housing recovery. But the Tokyo Bay area, brimming with high-rise apartments in locations like Toyosu and Kachidoki, is seen as a bellwether for the broader market because residents are known to buy them both as a place to live and assets to speculate on.