During the four-week period ended July 11, the average weekly share of homes for sale with a price drop passed 4% for the first time since September 2020.

Meanwhile, the Mortgage Bankers Association’s seasonally adjusted purchase index rose 8% from the previous week.

Strong growth of single-family construction spending drove the increase, while spending on multifamily construction was flat, the National Association of Home Builders said.

In Boston, the index jumped 2.5% month over month and 16.2% year over year. The monthly increase was slightly down from the 2.6% rise recorded in March. 

Inventory levels rebounded last month, finally showing signs of recovery following a year of historical declines.

Although pending sales are up 29% from last year, they are starting to slow down, dropping 9.7% from their peak four weeks ago.

Single-family housing starts were up 4.2% from April and 49.8% from May 2020, at 1,098,000, according to the U.S. Census Bureau and Department of Housing and Urban Development.

Housing inventory also saw an increase from year-ago levels last month.

Of the 99 million residential properties in the U.S., approximately 1.4 million (or 1.4%) are vacant this quarter, with “zombie” home rates increasing both quarterly (21%) and annually (5.6%).

Year over year, however, pending home sales were up 57.1%, the NAR said, citing its monthly Pending Home Sales Index.

Median home sales prices in Massachusetts continued to rise in April due to strong buyer demand and record-low inventory.

The median sales price of new homes sold in April was $372,400, up from $334,200 in March and $310,100 a year ago. 

The pace of housing-price gains in Boston quickened in March, according to the S&P CoreLogic Case-Shiller U.S. National Home Price NSA Index, which showed a 2.6% increase from February and a 14.9% increase from a year earlier, compared to a gain of 0.9% the previous month.

Housing inventory in the Boston area, meanwhile, remained below year-ago levels in April.

The number of buyers who locked in mortgage rates for second homes spiked to 178% year over year in April, according to a report from Redfin.