Zillow's Home Price Index Shows First National Price Decline Since 2012 — Is This the Start of the Crash?
Published: October 14, 2025 | By Mariusz Kurylo
Zillow's Home Value Index, which tracks estimated home values across the U.S. using a proprietary algorithm applied to millions of property data points, recorded its first year-over-year national decline since 2012 in October 2025 — an inflection point that housing market analysts had been debating for months as the leading question in residential real estate. The decline was modest: approximately negative 1.8% on a national basis over the trailing twelve months, compared to the peak annual gains of 20–24% recorded in 2021. But direction matters in asset markets, and the shift from rising to falling national home prices was a psychological and financial threshold with potentially significant consequences.
The S&P CoreLogic Case-Shiller National Home Price Index — considered by many economists to be the gold standard for measuring U.S. home price movements given its repeat-sales methodology — confirmed the trend with a slight lag, showing the national index essentially flat to slightly negative when adjusted for seasonal patterns, according to Bloomberg's analysis of the data. The two indexes use different methodologies (Zillow's includes more frequent updates and a broader property set), but their convergence on a declining trend carried more evidential weight than either measure alone.
For homeowners who purchased before 2020, the price decline was largely a paper matter — they still held enormous unrealized gains from the appreciation of prior years. But for the approximately 7–8 million households who purchased homes in the 2021–2022 peak period at elevated prices and with minimal down payments, a national price decline raised the possibility of negative equity — owing more on a mortgage than the home was worth.
Which Markets Led the Decline
The national decline was heavily influenced by sharp corrections in the markets that had appreciated most aggressively during the pandemic migration wave. Zillow Research's metro-level data, cited by the Wall Street Journal, showed year-over-year price declines ranging from 6% to 12% in the most overheated markets: Austin, Texas was showing approximately -9.2%; Boise, Idaho -8.7%; Phoenix, Arizona -6.4%; Las Vegas, Nevada -5.8%; and several Florida markets including Tampa and Jacksonville registering -4 to -7% declines.
These were the markets that had attracted pandemic-era migrants seeking more space and lower costs relative to coastal cities — and where prices had risen 50–80% in roughly two years. As migration flows normalized, remote work policies tightened, and affordability constraints reasserted themselves, these markets saw the demand side of their equation collapse faster than the supply side could adjust. New construction that had been planned in response to 2021–2022 demand was delivering into a market that no longer had that demand.
Bloomberg noted an important asymmetry in the price declines: while headline prices were falling, transaction volume had collapsed to even greater extremes, with home sales in many Sun Belt markets down 30–40% from peak levels. This made the price statistics somewhat murky — the homes that were selling were often distressed or unusual cases, while the bulk of the owner-occupied market remained frozen by the lock-in effect of low-rate mortgages. The statistical price decline was real but reflected a smaller sample of actual transactions than in a normal market.
How the Case-Shiller Methodology Differs From Zillow's
For readers trying to reconcile different data sources, the methodological differences between home price indexes matter considerably. The Case-Shiller index uses a "repeat sales" methodology: it tracks the change in price of the same property over time, comparing what a house sold for in one period to what that same house sold for in a prior period. This approach is considered highly accurate because it eliminates variation in the mix of homes transacted, but it has significant lags — the most recent data is typically two to three months old.
Zillow's index, by contrast, uses a "hedonic" model that estimates the value of all homes (not just those that transacted) based on a machine-learning algorithm trained on property characteristics, recent neighborhood sales, and other market data. This approach provides more timely updates and broader coverage but may be more prone to algorithmic bias in thin or unusual markets.
Reuters reported that the S&P CoreLogic Case-Shiller 20-City Composite — the most widely followed version of that index — was still showing small positive year-over-year gains through its most recent available data, even as more timely indicators like Zillow and Redfin showed declines. This discrepancy was creating confusion in media coverage and among consumers trying to assess whether prices were actually falling. Housing economists generally advised weighting both sources together and watching the directional trend rather than any single data point.
The Negative Equity Risk
For buyers who purchased at or near peak prices in 2021–2022, the most practically important question was not the philosophical debate between indexes but the concrete question of whether their specific home was now worth less than their mortgage balance. CNBC reported that Zillow Research estimated approximately 2.2 million homeowners had entered negative equity — also called being "underwater" — by fall 2025, primarily concentrated in markets with the sharpest price corrections.
The 2.2 million negative equity figure, while significant, was small compared to the approximately 12 million households who were underwater at the nadir of the 2008–2012 housing crisis. But the trajectory was concerning: each additional percentage point of national home price decline added roughly 300,000–400,000 households to the negative equity pool, based on housing economists' estimates of the distribution of loan-to-value ratios across the ownership stock.
Negative equity has several practical consequences. Homeowners who are underwater cannot sell their homes without bringing cash to closing — which means that the lock-in effect operates differently for them than for equity-rich owners. Rather than being locked in by a favorable mortgage rate, they are locked in by a negative equity position. They also cannot refinance easily, as lenders require a minimum equity cushion (typically 10–20%) for refinancing. And those who face life circumstances requiring a move — job relocation, family changes, financial emergency — are put in an extremely difficult position.
Historical Comparison: 2025 vs. 2006
The inevitable comparison to the 2006–2012 housing crash was both illuminating and cautionary. The 2006 decline, which preceded the financial crisis, began with a similar combination of factors: high prices, rising rates, declining affordability, and early-stage delinquency upticks in the most overextended markets. The Financial Times noted several important differences: today's mortgage market is predominantly 30-year fixed-rate loans rather than the adjustable-rate exotic mortgages that dominated 2006; today's borrowers generally have higher credit scores; and today's foreclosure pipeline, while growing, started from a historically low base.
But the similarities were also striking: the geographic concentration of stress in recently overheated markets, the lock-in dynamics that would keep supply tight even as demand fell, and the feedback between affordability and consumer confidence. The Wall Street Journal's housing desk noted that every housing cycle decline begins with analysts citing the differences from prior cycles as reasons the current correction will be more limited — and history suggests this confidence is frequently misplaced.
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Sources: Bloomberg, Reuters, The Wall Street Journal, Zillow Research, National Association of Realtors, CNBC
Disclaimer: This article is for informational and educational purposes only. It does not constitute financial, legal, or investment advice.