What Is Case-Shiller Index?
The Case-Shiller Index measures how home prices change over time by tracking the same properties as they sell again — the "repeat sales" method. It covers 20 metros including New York, Chicago, Los Angeles, Phoenix, and Tampa, plus national and composite indices. As of December 2025, the 20-City Composite showed 1.4% year-over-year appreciation, with massive regional divergence: Chicago led at +5.3%, New York at +5.1%, while Tampa fell -2.9%. Investors use it as a macro barometer — when your target market's Case-Shiller trend diverges from national, it signals either opportunity or warning. The index is published monthly with a two-month lag (December data released in late February), so it confirms trends rather than predicts them.
The S&P CoreLogic Case-Shiller Home Price Index is the most widely cited measure of U.S. residential home price movements, tracking repeat sales of single-family homes across 20 major metro areas and publishing both a 10-city and 20-city composite index.
At a Glance
- What it is: A repeat-sales home price index covering 20 U.S. metro areas
- Published by: S&P Dow Jones Indices (using Cotality/CoreLogic data)
- Frequency: Monthly, with a ~2-month lag
- Base value: 100 = January 2000
- December 2025 reading: 342.5 (20-City Composite, seasonally adjusted) — meaning prices are up ~242% since 2000
- Key use for investors: Tracking metro-level appreciation trends over time
How It Works
Repeat-sales methodology. Unlike simple median price indices (which shift when the mix of homes sold changes), Case-Shiller tracks the same individual houses over time. When a house sells in 2018 for $250,000 and again in 2025 for $310,000, that price pair feeds the index. By comparing thousands of these pairs, the index isolates true price appreciation from changes in the mix of homes trading. This makes it the gold standard for measuring whether property values are genuinely rising or falling, not just reflecting which neighborhoods happen to be active.
The 20-city composite and national index. The index covers Atlanta, Boston, Charlotte, Chicago, Cleveland, Dallas, Denver, Detroit, Las Vegas, Los Angeles, Miami, Minneapolis, New York, Phoenix, Portland, San Diego, San Francisco, Seattle, Tampa, and Washington D.C. The 20-City Composite is a weighted average of these metros. There is also a 10-City Composite (the original index) and a broader National Index that extends beyond the 20 metros. All are normalized to 100 in January 2000. The indices use a three-month moving average, which smooths short-term noise but adds to the reporting lag.
What recent data shows. The December 2025 data revealed a tale of two markets. Midwest and Northeast cities — Chicago (+5.3%), New York (+5.1%), Cleveland (+4.0%) — showed persistent strength driven by affordable price points and constrained supply. Sun Belt markets that boomed during 2020-2022 have cooled significantly: Tampa posted -2.9% year-over-year, its 14th consecutive month of annual declines. Nationally, the 1.4% annual gain trailed consumer inflation of 2.7%, meaning real home values effectively declined. For investors, this divergence highlights why local market analysis matters more than national headlines.
Real-World Example
Using Case-Shiller to time a Phoenix acquisition. Marcus has been watching Phoenix since 2021, when Case-Shiller showed 30%+ annual appreciation — too hot to buy for cash flow. By mid-2023, the index showed Phoenix appreciation slowing to 2.1%. By late 2025, it was barely positive at 0.8% year-over-year while the national index grew 1.4%. Marcus sees the cooling as a buying window: prices have stabilized, inventory has risen, and sellers are negotiating. He buys a $340,000 single-family rental that would have cost $375,000 at 2022 peak pricing. His pro-forma underwriting assumes 2% annual appreciation — conservative versus Phoenix's long-term Case-Shiller average of 4.5% — giving him margin of safety.
Pros & Cons
- Gold-standard methodology — repeat-sales approach controls for housing quality mix
- Metro-level granularity — lets you compare your target city against national trends
- Long historical dataset — goes back to 1987 for the 10-city, enabling cycle analysis
- Widely followed — lenders, economists, and media reference it, making it a shared language
- Free data — available on FRED and S&P's website
- Two-month reporting lag — December data arrives in late February, so it confirms rather than predicts
- Three-month moving average — smooths volatility but masks turning points
- Only 20 metros — secondary markets like Boise, Nashville, or Memphis are not individually tracked
- Single-family only — excludes condos, multifamily, and new construction
- National composite masks regional divergence — the headline number can mislead
Watch Out
- Don't use it as a crystal ball: The lag and smoothing mean Case-Shiller tells you where the market was, not where it is going. By the time the index confirms a downturn, prices may have already dropped 5-10%.
- Metro vs. submarket: Case-Shiller covers the entire MSA. Phoenix metro includes Scottsdale, Mesa, Gilbert, and Buckeye — each with very different dynamics. Layer in local market analysis at the zip-code level.
- Nominal vs. real: A 1.4% gain with 2.7% inflation is a real loss of purchasing power. Always compare Case-Shiller readings against CPI when evaluating appreciation.
- Cotality rebranding: CoreLogic rebranded to Cotality in 2025, so you may see "S&P Cotality Case-Shiller" in newer releases. Same data, different name.
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The Takeaway
The Case-Shiller Index is the most reliable measure of how home prices move over time, and every serious investor should track it for their target metros. Use it to identify cooling or heating trends, compare markets, and calibrate your appreciation assumptions in pro-forma underwriting. Just remember: it looks backward, covers only 20 metros, and the national composite can hide the regional story that matters most to your portfolio.