The frequency of bidding wars among buyers plunged in 2018, according to the real estate brokerage Redfin.

The company recently determined that 13 percent of buyers faced competition when making an offer in January, down from 53 percent in the year before. The frequency of bidding wars has typically oscillated over the course of the year, with competition increasing in the spring and falling off later in the year. In 2018, however, competition declined precipitously after peaking in the spring.

Redfin suggested that this is likely a result of increasing inventory as more homeowners put their properties on the market. In addition, home sales fell during the year as potential buyers had trouble finding an affordable home, with the buyers who did enter the market facing less competition.

"Buyers have heard that the market has slowed, so now they're trying to get all of their 'wants,' not just their 'needs,'" said Kalena Masching, a Redfin agent in Palo Alto, Calif. "They're waiting until they find a home that can check more boxes – for instance three bedrooms instead of two or a higher rated school. In general, they are being more judicious as they think through their purchase. Meanwhile, many sellers have not yet recognized that the market has shifted."

The drop in bidding wars has been most pronounced in some of the nation's most competitive housing markets. In San Francisco, Redfin agents found that just 18 percent of buyers faced competition in January – down from 82 percent in January 2018. The share of bidding wars fell 57 percentage points to 16 percent in Los Angeles and 54 percentage points to 15 percent in Seattle.

While the share of bidding wars continued to slide in some markets between December and January, others saw a slight uptick in competition. While agents in Raleigh, N.C. said none of their buyers' offers faced competition in December, 18 percent had competitors in January. The share of offers facing competition in Portland, Ore. rose from 8 percent in December to 19 percent in January.

Redfin expects that the market may prove more advantageous to buyers in 2019 as home price growth slows and listings spend more time on the market. Mortgage rates have also retreated about half a point after nearing 5 percent in late 2018, which might also encourage more buyers looking to enter the market.