The primary reason longtime home searchers haven’t bought a home yet is because they keep getting outbid, according to the National Association of Home Builders.

Presidents Day weekend marks the unofficial start of the spring housing market, but if you’re looking to get in this year, hold onto your wallet. Bidding wars are off the charts, even as home prices are rising rapidly.

The primary reason longtime home searchers haven’t bought a house yet is because they keep getting outbid. About 40% of potential buyers cited that in a new survey by the National Association of Home Builders. The reasons are flipped from a year earlier, when 44% said unaffordable prices were the biggest reason they hadn’t bought yet, and 19% cited getting outbid.

Well over half of all buyers, 56%, faced bidding wars on their offers in January, according to a Redfin survey. That is up from 52% in December. More than half of homes are now going under contract in less than two weeks.

“With so few new listings hitting the market, I expect bidding wars to become more common and involve even more potential buyers as we head into the spring homebuying season,” said Daryl Fairweather, chief economist at Redfin.

She advises buyers to be ready to go see properties the moment they hit the market and to get preapproved for a mortgage.

“But know when to back away if the price escalates more than you’re willing to pay,” Fairweather added.