Freddie Mac's weekly survey had the 30-year fixed at 7.28% on October 1. The week before it was 7.03%. A year ago it was 6.34%. Scroll back through Freddie's own series on FRED and you have to go to November 2023 to find a higher weekly print.That's the conforming loan, though, and almost nobody buys in Atherton with a conforming loan. San Mateo County's 2026 one-unit limit is $1,249,125. Past that you're in jumbo land, which in this town means pretty much every financed purchase.Jumbo moved too. The Optimal Blue 30-year jumbo index on FRED bottomed at 6.104% on February 20. It hit 7.562% on September 29 and sat at 7.526% on October 5. Bankrate's survey of big lenders this morning has the 30-year jumbo average at 7.63%, up from 7.45% last week. Two different data sets, about a tenth of a point apart. Same direction.The why is pretty plain. The Fed raised its benchmark 25 basis points on September 16, to 4% at the top of the range, per Inman. A week later HousingWire's Logan Mohtashami had the 10-year Treasury jumping from 4.96% to around 5.13% in a single session after hot PMI data and a hawkish speech from Fed governor Michael Barr, a level he said hadn't been seen since 2006. The next Fed meeting is October 27 and 28.Now put a real house under it.134 Hawthorne Drive hit the MLS on September 28 at $7,988,000. It's a 1950 California ranch in Lindenwood, four bedrooms, 2,110 square feet, on a 40,099 square foot lot (call it 0.92 acres) with a pool and pool house. The listing remarks pitch the chance "to create a future estate." At list that works out to $3,785 per square foot of house, which tells you the house isn't really what's being sold. Lindenwood ranches on near-acre lots got bid hard this summer. 1 Manzanita Road went for $11.3 million against an $8.25 million ask in August.The payment math is simple enough. Twenty percent down leaves a $6,390,400 loan. At February's 6.104% jumbo index, principal and interest is about $38,742 a month. At October 5's 7.526%, about $44,796. That's roughly $6,054 more every month, a bit over $72,000 a year, before property tax, insurance, or a single architect invoice for the estate the listing is dangling.Or flip it. The monthly payment that carried a $6.39 million loan in February now carries about $5.53 million. Something like $864,000 of borrowing power, gone in seven and a half months.The brokerage page for the listing runs its payment estimate at 6.75%, which gets you $41,448. That number already looks old.Does any of this cool Atherton off? My guess is less than the headlines suggest. Plenty of buyers at this price pay cash or borrow against a stock portfolio, and the Peninsula overbids kept landing right through the rate spike. The Real Deal reported that 160 Fawn Lane in Portola Valley, a 2021 build on an acre, sold September 29 for $8.5 million, more than half a million over asking, after under two weeks on market. The listing agent, Hugh Cornish, put it down to Portola Valley having almost no spec building because approvals drag, "so people will pay a premium for a finished product." Same story had a new build at 900 Wallea Drive in Menlo Park listed and closed the same day at $10.7 million, which looked like an off-market deal.Where it does bite is the lot-value buyer. Somebody paying $8 million for a 1950 ranch is often planning to borrow twice. Once for the land and once for the build. Both of those costs just went up, and the build loan runs the whole time the house can't be lived in. Those are the bidders who pushed 1 Manzanita 37% over ask. If a few of them sit this round out, the next one may clear closer to list. I'll be watching how 134 Hawthorne goes for exactly that reason.If you're financing anything in Atherton this fall, get actual written quotes from two or three lenders, including whoever holds your brokerage account. An index is an average of other people's loans. Bankrate's general 7/1 ARM average was 6.44% this morning. It's a broad table number that doesn't break out jumbo, but an ARM is worth pricing if you really expect to rebuild and refinance inside seven years. Think about lock timing around the October 28 Fed decision, and ask whether a float-down is available and what it costs.Sellers, the cash buyer reads the same headlines. Price for the person who has to finance, and the cash buyer will feel like they're getting a deal.Michael Williams is a Bay Area agent with Golden Gate Luxury (Turbohome Inc). Seventeen years in, more than $250M closed, formerly #1 at Flyhomes and Aalto, DRE #01780513. Golden Gate Luxury is not affiliated with Golden Gate Sotheby's.General market commentary only. For legal, tax, or lending questions, talk to the right licensed pro. Rates here are published averages and index readings that change daily, and the payment figures are simple principal and interest math, so get a real Loan Estimate before you write an offer.Also on Medium: https://medium.com/@michael_30207/rates-just-hit-their-highest-since-2023-run-the-math-on-an-8-million-atherton-ranch-5b5c46231760
Michael Williams
Luxury Specialist
Area served: Sausalito, Marin County, CA, Menlo Park, CA, San Francisco, CA
Expertise: First-Time Buyer, Luxury, Zoning Knowledge