What $10M to $20M Actually Buys You in Hillsborough, California

A client asked me recently whether there was an upper limit to buying homes in Hillsborough, California, and whether I had anything above $20M at all. I have had a version of that conversation more than once this year, so I decided to stop guessing. My team and I pulled every Hillsborough real estate sale of $10M and up going back 10 years, which came to 96 sales across 90 homes, and then we looked at what that money actually bought in each of those years.

The answer surprised me. Over the last decade the price of entry to this market barely moved, but what a buyer receives for it changed completely. Below is everything we found, including which Hillsborough neighborhoods cost the most per square foot, how the town compares with Atherton, Menlo Park and Burlingame, and 5 pairs of homes that sold for nearly the same money and could not be more different.

The 5 things worth knowing before you read further

• In 2017, exactly 1 home in Hillsborough sold for $10M or more. In 2026 there have already been 16, and that is only through 08/28/2026.

• Appreciation at this price point does not show up as a bigger price tag. It shows up as less house and a lot less land for the same money.

• At the median, the house covers only about 20% of the lot, so roughly 4 fifths of what a buyer pays for here is land and setting.

• The condition of a home drives its price per square foot more than its size does. Two homes that closed within $500,000 of each other came in almost 2x apart per square foot.

• Of the 26 homes that sold at $10M and up in the last 12 months, 11 closed with 0 days on market. That is 42% of this market that was effectively sold through relationships before a buyer ever found it online.

The AI money behind the Peninsula surge

When a private company like OpenAI or Anthropic runs a tender offer, which is a company-organized sale that lets employees cash out part of their private shares before an IPO, the liquidity in the market goes up dramatically. Employees who were holding stock they could not spend are suddenly holding cash, and they start looking for somewhere to put it. Real estate is one of the most common answers.

What that money is doing to prices

The clearest sign that this new wave of wealth is translating into cash-heavy home buying is the size of the down payments. Realtor.com found that the median down payment on the top 10% of Bay Area listings held at 35% in 2025, compared with 28.4% before 2023. That stands out because other tech and wealth hubs did not show the same pattern: Austin, Miami and New York all returned to their normal levels as mortgage rates eased. The Bay Area didn’t.

The difference is especially relevant to Hillsborough CA real estate, where the market sits at the very high end of the Bay Area housing spectrum. As Realtor.com’s economist put it, “Austin has tech. New York has wealth. Both saw their luxury down payment shares normalize as rates came down. The Bay Area did not. The divergence maps directly to when AI equity liquidity events accelerated.”

And that willingness to bring more cash to the table appears to be giving buyers considerably more firepower when they compete for homes. In San Francisco, the number of homes selling for at least $1 million over asking jumped from just 6 in the first half of 2024 to 8 in the first half of 2025—and then to 144 in the first half of 2026. The San Francisco Standard reported

The broader market tells a similar story. About 30% of home sales in the San Francisco metro area were all-cash transactions between April and June of 2026, up from under 20% in 2021. NBC Bay Area reported When buyers are less constrained by mortgage financing, they can move faster, waive financing contingencies and, in some cases, simply bid more aggressively.

The effect is particularly visible at the top end of the market. San Francisco luxury home sales rose 22.2% year over year in the first quarter, with the median luxury price reaching $6.8 million, up 9%, according to Redfin. Non-luxury prices, by comparison, moved just 0.1%.

That contrast is important when looking at Hillsborough CA home prices and the broader Hillsborough CA real estate market. The impact of new wealth is not necessarily showing up evenly across every segment of the market. Instead, the sharpest effects are appearing where high-net-worth buyers have the greatest purchasing power: at the luxury end, where large cash positions can translate into more aggressive offers and, ultimately, higher prices.

Where it lands on the Peninsula

The effect started in San Francisco, but it hasn’t stayed there. It has been moving south, into the Peninsula and increasingly into places like Palo Alto, Atherton and Hillsborough. At a Palo Alto open house in August, one agent said that every single person who came through was from San Francisco. The Almanac reported

The clearest example may be Hillsborough itself. In August 2026, an estate sold for $70 million, according to ABC7 News reportedly to a 31-year-old employee at an AI company who is rumored to be an xAI cofounder. The listing agent said it was the highest sale ever recorded in Hillsborough and the highest in Northern California this year. She also confirmed that the buyer works in artificial intelligence and wanted to be close to SFO, San Francisco and Silicon Valley. For Hillsborough CA real estate, it is hard to imagine a more vivid illustration of the connection between AI wealth and the local housing market.

And buyers aren’t necessarily looking for finished homes. Some are paying extraordinary sums for the opportunity to build one themselves. On the Peninsula, buyers are now paying $10 million to $11 million for land alone. The Almanac reported A one-acre lot on Fairview Avenue in Atherton, for example, was asking $7.8 million and ultimately sold for $10.7 million.

The numbers are rising even beyond the most headline-grabbing deals. In Palo Alto, the price per square foot reached $2,316, up from $1,988 a year earlier, according to The Almanac. Luxury sales across the San Francisco metro rose 39.3% in the first half of 2026, compared with 15.1% for the middle market. The Almanac reported

San Mateo County’s higher-end market is showing the same pattern. Homes in the 65th to 95th percentile of estimated value grew more than any other home type in the Bay Area over the past year, according to a report cited by Yahoo Finance, with Atherton, Portola Valley and Woodside among the fastest-appreciating markets. One agent summed up the dynamic bluntly: “The tech wealth effect is putting real liquidity into the hands of local buyers.”

And the public-market numbers help explain why that liquidity can be so large. Between the end of 2023 and the end of 2025, NVIDIA added $3.31 trillion in market value, Alphabet added $2.03 trillion, and Meta added $761 billion. Those figures represent company value, not cash sitting in anyone’s bank account, and these are global companies rather than Bay Area companies. But they help explain the backdrop to a market where the checks—and the bids—keep getting bigger.

Hillsborough, CA home prices compared with Atherton, Menlo Park and Burlingame

Everything in this section covers all single-family sales in every price range, not only the $10M and up market, and 2026 runs through the end of August. I lead with the median rather than the average, because in a market this top-heavy a handful of very large sales pull the average away from what a typical home actually costs.

The hierarchy is clear. In 2026, Atherton is at $11.3 million, followed by Hillsborough at $6.5 million, Menlo Park at $3.5 million, Burlingame at $3.3 million, and San Mateo County as a whole at $2.1 million.

That puts Hillsborough firmly in second place among these markets—and at roughly three times the county median. But the averages tell a more nuanced story about just how top-heavy each market is. In Hillsborough, the average price is $8.21 million against a median of $6.5 million, putting the average 26% above the median. That is the widest gap among the four cities. In Burlingame, by comparison, the gap is just 7%.

San Mateo County has the widest gap of all, at 38%, but for a different reason. In Hillsborough, the spread is driven by a handful of very large sales within an already expensive town. At the county level, the distortion comes from the distance between markets: the county-wide figure effectively averages a place like Atherton against everywhere else. The result is a useful reminder that the median can sometimes tell you more about the typical Hillsborough CA home price than the average—especially in a market where a small number of extraordinary sales can pull the headline number sharply upward.

Where the real appreciation shows up: price per square foot

A median price tells you what the middle sale was in a given year, and it moves with whatever happened to sell. Price per square foot holds size roughly constant, so it answers the question a buyer actually cares about, which is what a foot of house in each town costs now compared with 11 years ago.

• All 4 of these cities beat the county, and Hillsborough beat it by 27 points. The more striking part is that the most expensive towns are appreciating at a faster rate than the cheaper ones and faster than the county overall.

• The top 3 cities are within 8 points of each other, so Hillsborough is not out ahead on its own. It belongs to a tight, fast-appreciating luxury tier on the Peninsula.

• The county line is worth pausing on. $1,276 per square foot is real appreciation, but that line goes almost flat after 2022 while all 4 city lines keep climbing. The gains of the last few years landed at the top of the market rather than across it.

What a decade of appreciation actually did in Hillsborough

A decade ago, $10M in Hillsborough barely happened

• Across 10 years there were 96 sales of $10M and up, covering 90 distinct homes, because 6 properties sold twice.

• In 2016 there were 4 of those sales. In 2017 there was 1.

• In 2026 there have been 16 through 08/28/2026, and another 6 by year end would put 2026 at 22.

• The growth did not arrive steadily. It came in 2 waves, with 31 sales in 2021 and 2022 and 29 in 2025 and 2026, and those 2 waves are 62.5% of the entire decade. The quiet stretch was 2023 and 2024, which is exactly when rates were at their highest.

Price per square foot rose 30% across the decade

• In the $10M to $20M range, a square foot went from $1,515 in 2016 to 2018, up to $1,973 in 2025 and 2026. That is 30% over 9 years, or roughly 3% a year.

• The timing matters more than the total. Price per square foot was essentially flat from 2016 all the way through 2021, and every bit of the movement came after 2022.

• Across every price range in Hillsborough, a square foot went from $1,332 in 2021 to $1,706 in 2026, which is 28.1% in 5 years, or about 5.1% a year against 4.8% a year across the full 11 years. The last 5 years ran hotter than the decade, and the last year on its own was up 14.2%.

Price per square foot and Sale Price Trend in Hillsborough

The most striking change in Hillsborough may be what $10 million to $20 million actually buys today. Back in 2016 to 2018, that price range bought a median of 8,092 square feet of house on a 72,310-square-foot lot. Today, the same money buys a median of 6,078 square feet on just 32,560 square feet of land. In other words, buyers are getting 25% less house and 55% less land for roughly the same price range.

The shift is even clearer at the lower end of the market. Between 2016 and 2018, the smallest home to sell for $10 million was 6,831 square feet. Today, a 4,082-square-foot home can clear that threshold. One example is 615 Devon Drive, which sold for $11 million. 615 Devon Drive listing

A decade ago, no home under 6,000 square feet and no lot under 25,000 square feet reached $10 million in Hillsborough. Today, 42% of sales are homes under 6,000 square feet, while 31% are lots under 25,000 square feet. The share of sales on an acre or more has also fallen from 75% to 39%.

But this is not simply a story of buyers settling for less. The definition of what makes a desirable Hillsborough home appears to be changing, too. A well-finished 4,000- to 5,000-square-foot home can be just as sought after as a much larger estate, and often more so. Clients regularly say they would rather have a good-sized home in a great location with good topography than a massive house filled with rooms they will never use.

And that gets to the heart of what buyers are actually paying for in Hillsborough. At the median, the house covers only about 20% of the lot. Four-fifths of what a buyer is paying for is the land and the setting—not the interior square footage.

The most and least expensive neighborhoods in Hillsborough, CA

Hillsborough has 14 MLS areas, and the spread between them is wider than most people expect. If the land is what a buyer is really paying for, then where that land is matters more than how much house is on it.

• Over the last 10 years, Ryan Tract is the most expensive pocket in Hillsborough at $1,742 per square foot.

• Hillsborough Knolls is the least expensive at $1,199, with Hillsborough Park just above it at $1,219. That is a 45% spread between pockets inside the same town, measured over the same 10 years of sales.

• On median sale price the spread is wider still. The median home in Ryan Tract is $7.49M and in Tobin Clark Estate it is $4.80M, which is 56% apart.

• The gap between average and median shows which pockets a few big sales are carrying. Homeplace runs 20.2% above its median and Brewer Subdivision runs 19.6%, while Hillsborough Hills runs only 5.3%.

• Hillsborough Knolls is the interesting one. It has the lowest price per square foot in town but the 4th highest median, which points to larger homes. If square footage is what you want for your money, Knolls is where you are most likely to find it.

Same money, different home: 5 Hillsborough comparisons

These are 5 pairs of closed sales from the trailing 12 months. Within each pair the 2 homes sold for nearly the same money, and in every case what the buyer received was completely different.

• 2077 Forest View Avenue and 45 Calaveras Court both closed at $10.2M. Forest View is 121 years old and 5,610 S/F on 1.68 acres, and it sold with 0 days on market. Calaveras is 1 year old and 7,132 S/F on 4.08 acres, and it took 300 days.

• 225 Tobin Clark Drive closed at $10.5M for 8,145 S/F, and 615 Devon Drive closed at $11M for 4,082 S/F. The Devon buyer paid $500,000 more for roughly half the house, because Devon is a turnkey designer remodel in lower Hillsborough while Tobin Clark is an unremodeled 1991 chateau in the high hills.

• 655 Hayne Road and 1221 Kenilworth Road both closed at $10.75M. Kenilworth is brand new with 20% more house, and Hayne comes with 64% more land. At this price point in Hillsborough you rarely get both.

• 7 Windsor Drive at $12.3M and 20 Pine Court at $12.4M are $100,000 apart. Windsor closed at $2,904 per S/F, the highest of any sale in the range all year, on the smallest lot in the range. Pine Court gave its buyer 47% more house and roughly 3 times the land. Both sold with 0 days on market.

• 1810 Brookvale Road at $18.81M and 925 Seabury Road at $19.8M are $990,000 apart, and Seabury is nearly double the house at 54% of the price per square foot.

What all 5 pairs have in common

• In every pair, the home with the higher price per square foot is the smaller one. Size and price per foot move in opposite directions at this level.

• The premium attaches to 2 things, which are the pocket and the condition. It does not attach to square footage.

The bottom line for Hillsborough buyers and sellers

The price tag tells you almost nothing about what you are getting. We looked at 2 homes $500,000 apart where one was twice the size of the other, and 2 homes that closed at the identical price where one came with 64% more land. So at $10M to $13M in Hillsborough, the question is not how much house you can buy. It is which pocket you want to be in, and what condition you are willing to take on.

The second thing the data made clear is that at this level the money is attached to the land and the location. At the median, the house covers about 20% of the lot. You are buying the setting, and then you are deciding what to do with the house that happens to be on it.

And there is very little of it to choose from. Across a full year this entire range trades at about 2 sales a month in the whole town, and 42% of those sales never reached the open market at all. When something good comes up, it does not last.

For sellers the read is simpler. A modern, fully remodeled home commands a large premium per square foot at this price point, and buyers here are not looking for projects. If you are weighing whether to renovate before listing, the price per square foot data in this post is the strongest argument for doing it.

Frequently asked questions about Hillsborough, CA real estate

What county is Hillsborough, CA in?

Hillsborough is in San Mateo County, California, on the San Francisco Peninsula. Its zip code is 94010, which it shares with Burlingame. It should not be confused with Hillsborough, North Carolina.

How much does a home cost in Hillsborough, CA?

The median single-family sale price in Hillsborough is $6.5M in 2026 through the end of August, across all price ranges. The average is $8.21M, which runs 26% higher because a small number of very large sales pull it up. Price per square foot is $1,706.

Is Hillsborough, CA expensive?

Yes, and it is the second most expensive of the Peninsula luxury towns we track. Hillsborough’s median of $6.5M is roughly 3 times the San Mateo County median of $2.1M, and it is below Atherton at $11.3M but above Menlo Park at $3.5M and Burlingame at $3.3M.

Which Hillsborough neighborhood is the most expensive?

Measured on price per square foot over the last 10 years, Ryan Tract is the most expensive at $1,742. On median sale price, Ryan Tract also leads at $7.49M. The least expensive pockets are Hillsborough Knolls at $1,199 per square foot and Hillsborough Park at $1,219.

Is Hillsborough appreciating faster than San Mateo County?

Yes, by a wide margin. Between 2015 and 2026, price per square foot in Hillsborough rose 68.1% against 41.2% for San Mateo County as a whole, which is a gap of 27 points. Atherton led the group at 74.6%.

How many homes in Hillsborough sell for over $10M?

There were 96 sales of $10M and up over the last 10 years, across 90 distinct homes. The annual count went from 4 in 2016 and 1 in 2017 to 13 in 2025 and 16 in 2026 through the end of August.

Is Hillsborough, CA a good place to live?

That depends entirely on what you are optimizing for, and the neighborhood matters more than the town. Lower Hillsborough pockets such as Homeplace are flat and walkable to downtown Burlingame. Upper pockets such as Tobin Clark Estate offer views and acreage but are gated and car-dependent. For more on schools, lot sizes and neighborhood character, see livinginsanmateocounty.com.

Methodology and sources

• All Hillsborough, Atherton, Menlo Park, Burlingame and San Mateo County sale figures come from MLSListings exports pulled in September 2026. Figures for 2026 run through 08/28/2026 and are therefore partial-year.

• The $10M and up analysis covers 96 closed sales across 90 distinct homes from 2016 through 08/28/2026. The 12-month comparison set covers 26 closed sales, of which 25 fall between $10M and $20M.

• Price per square foot figures are the volume-weighted ratio reported by MLS, not a median of individual ratios.

• The projection of 22 sales for 2026 is an estimate and not a recorded figure. The pace through 08/28/2026, which is one sale every 15 days, would give 24.

• Every third-party figure in this post links to its original source and was verified on 09/10/2026.

Thinking about buying or selling in Hillsborough?

Which pocket is right for you depends on what you are optimizing for, and that is a much easier conversation to have about your specific situation than it is to cover in an article. I am Raziel Ungar, and I have helped hundreds of buyers and sellers across San Mateo County. If you are weighing a move in Hillsborough or anywhere on the Peninsula, I would be glad to be your choice of realtor.

Internal links to add: the AI wealth article, the Burlingame lot sizes by neighborhood article, the July 2026 San Mateo County market update, and the upcoming Hillsborough lot analysis once it publishes.

This article is copyrighted by Raziel Ungar and may not be reproduced or copied without express written permission.