Home prices set another record in April, even as mortgage rates rose and the supply of homes for sale increased. Usually, under those circumstances, prices would weaken, but today’s housing market is unlike any other in recent history.

Prices in April rose 6.3% compared with the year-earlier month, according to the S&P CoreLogic Case-Shiller National Home Price Index. It marks the second straight month that the national index jumped at least 1% over its previous all-time high.

Although this is a three-month moving average, it’s important to note that those price gains come even as the average rate on the 30-year fixed mortgage jumped sharply in April, from 6.9% to 7.5%, according to Mortgage News Daily.

“2024 is closely tracking the strong start observed last year, where March and April posted the largest rise seen prior to a slowdown in the summer and fall,” said Brian Luke, head of commodities, real and digital assets at S&P Dow Jones Indices, in a news release. “Heading into summer, the market is at an all-time high, once again testing its resilience against the historically more active time of the year.”

The only potential sign of relief is that the annual and monthly gains on the price index are slowing a little bit. March’s annual gain was 6.5%.

Still, it feeds into what is now one of the least affordable housing markets in U.S. history for both homeownership and renting. The housing cost burden has hit a record, according to a new report from Harvard’s Joint Center for Housing Studies.

Home prices are now 47% higher than they were in early 2020, with the median sale price now five times the median household income, according to the study.

For renters, even though rent growth is slowing due to a big increase in new apartment units this year, prices are still 26% higher than they were in 2020 and rising in three out of every five markets.

Half of all renter households — more than 22 million — spent more than 30% of their income on housing, which is considered “cost burdened” by HJCH. Twelve million of those households spend more than half their income on rent.

For homeowners, 20 million are considered cost burdened by their monthly payments.

All of those cost-burdened levels represent records.

Homeowners are also facing a sharp increase in insurance premiums, up an average 21% between 2022 and 2023, according to the HJCH report, and property taxes are also rising.

Prices continue to be supported by an imbalance in supply and demand. Housing supply was already low before the Covid pandemic hit, because homebuilders had yet to recover from the 2008 financial crisis. Then there was a pandemic-induced run on housing, causing supply to drop to record lows for several years. Homebuilders couldn’t keep up.

Supply is now rising, with an 11% increase in new listings in April from March, according to Zillow, and a 16% increase from April 2023. That pushed total for-sale inventory up 18% year over year. While that might sound like a lot, supply is still quite lean, especially compared with the strong demand.

“The rapid and sudden increase in mortgage rates in April pushed housing affordability further out of reach for many potential buyers while some who could still afford held back,” said Zillow’s senior economist Orphe Divounguy in a release. “As a result, the share of listings with a price cut shot up to 22.4% in April, the highest rate for April in the past six years, and a significant step up from 17.2% a year earlier.”

But he added that despite the relative slowdown in April sales, homes that were priced well sold in just 13 days, only three days slower than in April 2023.

In May, inventory rose to a 3.7-month supply. A six-month supply is considered a balanced market between buyer and seller.