A “For Rent” sign in front of an apartment building on St. Paul Street in Brookline, MA, on September 12, 2025. Boston Globe | Boston Globe | Getty ImagesA version of this article first appeared in the CNBC Property Play newsletter with Diana Olick. Property Play covers new and evolving opportunities for the real estate investor, from individuals to venture capitalists, private equity funds, family offices, institutional investors and large public companies. Sign up to receive future editions, straight to your inbox.A slew of new supply is still making its way through the multifamily housing market. That, coupled with weakening demand, especially from the youngest workers, is pushing vacancies up and rents down. The national median rent for apartments fell 1% in November from October, and now stands at $1,367, according to Apartment List. It was the fourth consecutive month-over-month decline. Apartment rents are down 1.1% from November 2024 and have fallen 5.2% from their 2022 peak. “Earlier this year, it appeared that annual growth was on track to flip positive for the first time since mid-2023; however, that rebound stalled out and reversed course during a particularly slow summer,” according to Apartment List researchers.After hitting a record high for this index, which dates back to 2017, in October, the national multifamily vacancy rate remained at 7.2% in November. The historic surge in multifamily construction over the past few years is now pulling back, but a good supply of new units is still coming online at a time of much weaker demand. The fall historically sees the biggest slowdown in multifamily rents, but this year it’s even more pronounced. CoStar reported the biggest monthly drops in median rent it had seen in 15 years of tracking. The primary reason is that more young people are struggling to form new households. “That 18- to 34-year-old group … I think it’s up to 32.5% of those now are living with family, and that’s the highest it’s been in a while,” said Grant Montgomery, CoStar’s national director of multifamily analytics. “I think it reflects high rental costs that have risen over the years, as well as the tougher job market for …