The biggest complaint in today’s housing market might not be the high prices or even rising mortgage interest rates. It’s that there aren’t enough homes for sale, a situation that appears to only be getting worse.

So why aren’t sellers selling? Their top concern is putting their current residence on the market before finding a new one to purchase, according to a recent Realtor.com® survey. About a third of sellers in February were worried about finding a new home they could afford.

The insights are based on a series of surveys of 2,400 to 3,000 visitors to Realtor.com over a three-month period. Only responses from visitors who are homeowners, including active and prospective sellers, were included in this report.

“Sellers may not want to buy first, but in reality, they may need to sell first to get cash for their next purchase. They may need a larger down payment to control the size of their mortgage, because mortgage rates are so high,” says Jiayi Xu, an economist at Realtor.com. The more money they put down, the lower their mortgage payments will be.

Many homeowners who would have traded up into larger, nicer homes or downsized into smaller ones have been reluctant to sell and let go of their record-low mortgage rates. That’s resulted in about a fifth fewer new home listings in April than there were a year earlier, worsening the housing shortage, according to the latest Realtor.com data.

Since many homeowners either bought their properties at a lower rate or refinanced during the COVID-19 pandemic, when rates fell to as low as mid-2%, they’re understandably reluctant to buy a home at today’s rates in the mid-6% range. That has been the main financial reason stopping homeowners from listing their homes since 2022.

Sellers are also worried about the state of the housing market. While it’s still not a buyer’s market, the days of homes selling moments after they went up for sale and buyers waiving all contingencies appear to be over. About a fifth of homeowners in reported February they were concerned about slowing buyer demand in their area and that sellers aren’t receiving good offers. That was more than double the worry that potential sellers expressed a year earlier.

“A lot of sellers want to wait until home prices go high again,” said Xu. “Given all of the uncertainties in the housing market, I don’t [think] that’s going to happen soon.”

Other concerns include the work—and cost—involved in getting their homes ready to list. High inflation driving up costs was a particular concern.

“A lot of people overlook the cost of repairing their homes and getting them ready for market,” says Xu. “The costs are much higher [than] the same time last year.”