Why Inventory Levels Matter So Much

People love talking about mortgage rates. Headlines obsess over inflation. But in real estate, especially in San Francisco, one factor quietly shapes almost everything else: inventory.

Put simply, inventory is the number of homes available for sale at any given time. And right now in San Francisco, there just aren’t that many. In our latest market update, inventory levels were still sitting nearly 40% below last year’s numbers, even as buyer demand continues to surge. That imbalance is a huge reason why single-family homes are currently selling for a staggering 26% over asking price. When there are far more buyers than available homes, things get competitive fast. Very fast.

Low inventory changes buyer behavior almost immediately. Buyers become more aggressive, move faster, and often make stronger offers because they know another opportunity may not come around anytime soon. It’s why we’re seeing homes sell in just 11 median days on market, and why bidding wars have become almost routine again across neighborhoods like Noe Valley, Cow Hollow, and beyond. In a market with limited choices, buyers don’t just compete on price — they compete on speed, terms, and certainty.

What makes San Francisco particularly interesting right now is that the city isn’t behaving like much of the broader national market. Across many U.S. metros, inventory has been gradually improving and buyers are gaining more negotiating power. But San Francisco continues operating in its own little economic universe. Renewed optimism around the tech sector, combined with AI-driven wealth creation and a large pool of high-liquidity buyers, is helping sustain demand even while mortgage rate uncertainty continues dominating national headlines. In other words: higher rates matter, but supply still matters more.

This is also why the usual “summer slowdown” may not really happen this year. Traditionally, inventory and buyer activity begin cooling during the summer months. But many sellers are now seeing how intense competition has become and deciding they’d rather list sooner rather than later. Ironically, the lack of inventory itself may actually encourage more inventory to hit the market. Because when your neighbor sells for half a million over asking in less than two weeks, suddenly that “maybe next year” conversation starts changing pretty quickly.

At the end of the day, inventory is the foundation underneath almost every housing market trend people care about — pricing, competition, negotiation power, days on market, and even buyer psychology. And right now in San Francisco, inventory remains extraordinarily tight. Until that changes in a meaningful way, the market may continue doing what it’s been doing best lately: surprising people.