Almost every big tech IPO of 2019 (Uber, Lyft, Pinterest, Slack, Postmates, Airbnb, Instacart) is headquartered in SF. It's undeniable that the center of silicon valley is slowly shifting north.
Back in the day, the name Silicon Valley came from the fact that most of the companies worked with actual silicon. Most of them were based near Mt. View because 1) The land was a lot cheaper than SF and 2) Most of the capital was there.
The "new" SV is north because all the consumer websites set up shop in SF since all they needed was office and not chip fabs, and they were mostly being worked on by younger folks who wanted to live in the city proper.
Now we have a bifurcated ecosystem where all the hardware folks (and companies) are still in the south bay (and don't kid yourself, there are a ton of hardware startups down here still) and all the consumer stuff is up north.
You just hear about the consumer stuff more because most of the silicon companies are B2B.
Facebook, Google, Apple, Yahoo, Adobe, Intuit, and Microsoft & Amazon's Bay Area offices are all in SV.
I'd really divide it by era. Anything founded before 2005 is in Silicon Valley; after that is in San Francisco. I actually think YCombinator is a big driver of that; they funded younger startup founders (largely Millenials rather than Gen-Xers) who wanted to live in the city.
Actually Amazon's offices in SF are split between the valley and downtown, depending on what they're working on. I think hardware and embedded is out in the valley. Software / services are more in SF. And that's not counting Twitch which is in the Financial.
A9 (Amazon's search & advertising subsidiary) is in Palo Alto. That's the office I'm most familiar with, although perhaps that's because of the revolving door of high-level employees between it and Google.
The "back in the day" for silicon you are referring to was pre-80s. You skipped an entire generation of software companies headquartered in South Bay that have gained prominence since then — Google, Facebook, Oracle, eBay, Cisco, Adobe, Nvidia, Netflix and lots more.
Yes, I did skip a section, but only because it didn't feel super relevant. Having worked at two of those companies myself, I'm well aware of the phase in the middle (although Cisco and Nvidia are actual silicon companies).
As a fun side note, the only reason Netflix is in Los Gatos is because the founder wanted it in Santa Cruz, where he lived, but was convinced no one would work there because it would be too far, so he picked the city closest to Santa Cruz that people would still consider Silicon Valley.
Have any of those companies gone public yet? While I believe there is a shift north, I also believe a lot of the newer companies won't exist in 5 years. I guess I feel SF is still a lot more ephemeral than its southern neighbors.
I'm not a specialist by any means but isn't most of the boomers' money held by pension funds and the like? Which pension funds and the like mostly use passive-investing nowadays (or techniques used by the passive-investing types, like index-tracking), which actually means buying stocks and being present on the equity markets.
What I mean is that it's not the boomers' decision to make in regards to where their money is actually invested.
Treasury bills. Very short-term government bonds that don't pay a coupon, just typically sell at a tiny discount to face value. Little risk of any kind (default, interest rate), pretty much the most secure security there is.
The "new" SV is north because all the consumer websites set up shop in SF since all they needed was office and not chip fabs, and they were mostly being worked on by younger folks who wanted to live in the city proper.
Now we have a bifurcated ecosystem where all the hardware folks (and companies) are still in the south bay (and don't kid yourself, there are a ton of hardware startups down here still) and all the consumer stuff is up north.
You just hear about the consumer stuff more because most of the silicon companies are B2B.