If you follow housing news even loosely, you probably saw two or three headlines this week about home prices, and there's a decent chance they didn't agree with each other. One report says prices are up about 1.9% from a year ago. Another says 2.6%. A third, looking at homes that actually closed rather than an index, says 1.6%. A fourth puts the number at 2.2%. None of these reports are wrong. They're just not measuring the same thing, and the gap between them is bigger than most people realize.
This week alone, S&P Cotality released its closely watched Case-Shiller National Home Price Index, showing a 1.9% annual gain for July, with its 20-city composite up 2.5% and its 10-city composite up 3.4%, according to the September 29 release. On the same day, the Federal Housing Finance Agency published its own House Price Index for July, showing a 2.6% annual gain and a 0.3% increase from June. Earlier in the month, the National Association of Realtors reported that the median price of an existing home that actually sold in August was $429,100, up 1.6% from a year earlier. And Redfin's four-week rolling snapshot, covering the period ending September 6, put the median sale price at $398,637, up 2.2% year over year.
So which one is right. Honestly, all of them, for what each is actually built to measure. The frustrating part is that almost nobody explains the difference before quoting the number, which is how you end up with four headlines in one week that all sound like they're describing the same market and clearly aren't.
So Why Don't the Numbers Match?
Case-Shiller and FHFA are repeat-sales indices. Instead of looking at every home that sold in a given month, they track the same individual properties over time and compare what they sold for this time versus last time. That approach is good at isolating actual price appreciation, separate from the mix of homes selling, but it comes with a real cost: both indices are built on closed sales, which means July's numbers mostly reflect contracts signed back in May and June, when mortgage rates were still in the high 6% range rather than the 7.03% Freddie Mac reported for the week of September 24. You're reading a snapshot of a market that has already moved on.
NAR's median sale price is a different animal entirely. It's simply the middle value of every existing home that closed in a given month, which means it swings with the mix of what's selling, not just how much any individual home appreciated. If more $250,000 starter homes close in a given month, the median drops, even if every single home on the market gained value. If move-up buyers dominate instead, the median rises for the opposite reason.
Redfin's weekly tracker measures something closer to real time, since it's built on a rolling four-week window instead of a full calendar month, but that speed comes with more noise and a smaller, somewhat different sample of markets than NAR covers nationally. It's genuinely useful for spotting a turn early. It's less useful as a precise, apples-to-apples number to compare against a monthly report six weeks later.
None of that makes any of these reports untrustworthy. It just means a single headline number, ripped out of its methodology, tells you almost nothing about what's happening in your specific market or your specific price range.
What This Actually Means for You
HouseJet has been tracking this gap for months, and it genuinely doesn't think the fix is picking a favorite index. The fix is using the right tool for the question you're actually asking. If you want to know whether home values broadly are appreciating or declining, a repeat-sales index like Case-Shiller or FHFA is the more honest read, even with its two-month lag. If you want to know what a typical home is actually trading for right now in dollar terms, NAR's median is closer, with the caveat that it's still a national blend of very different regional markets. Neither one tells you what a three-bedroom colonial in your specific zip code sold for last month, and that's the number that actually matters when you're the one making an offer.
Here's the catch, though, and it's worth sitting with. Even the most carefully chosen national index is still national. Case-Shiller's own data shows Chicago prices up 6.9% year over year while Denver is down 1.1% and Seattle is down 1.6%, all in the same July report. Averaging those together into one number and applying it to your own decision is a little like averaging the temperature in Phoenix and Anchorage and calling it the weather. The methodology fight matters less than the geography one, and both matter less than what closed on your own street in the last thirty to sixty days.
Ask your agent for actual closed comps in your target neighborhood from the last thirty to sixty days, not a national number. That's the single best substitute for any index, because it captures both the true price level and the local mix at the same time, without any of the averaging problems above.
Match the report to the decision you're making. If you're deciding whether to wait out a downturn or jump in now, a repeat-sales index tells you the broader trend. If you're sizing up whether a specific asking price is reasonable, recent closed sales in that neighborhood beat any national figure every time.
Get your actual numbers from a person, not a press release. A mortgage professional can run today's rate against today's price for the specific loan you'd actually qualify for, which is a more useful exercise than trying to back into your future payment from a national median that's already a month or two stale by the time it's published.
None of this means the national numbers are useless. They're a reasonable gut check on direction, and worth knowing before you walk into a negotiation with unrealistic expectations in either direction. They're just not a substitute for looking at your own market, and treating any one of them as gospel is how buyers end up either overpaying out of panic or underbidding out of false confidence.
The market isn't lying to you. It's just being reported by four different people with four different rulers. Bring your own tape measure before you make an offer.
