SEMI is moving its flagship semiconductor conference from Moscone Center to Phoenix permanently starting in 2027, ending a 50-plus-year Bay Area run — a real subtraction from a convention calendar the city keeps citing as proof of recovery.

Semicon West, one of the semiconductor industry's oldest trade gatherings, will hold its last scheduled San Francisco edition Oct. 13–15 at Moscone Center and then move to Phoenix for good, SEMI, the Milpitas-based association that runs the event, announced last week. The decision — first reported by the SF Chronicle and confirmed by SEMI's own release and by outlets including Phoenix NPR affiliate KJZZ and the trade site TechTimes — ends a more than 50-year association with the Bay Area dating to 1976.

The show lands at the Phoenix Convention Center on a new spring schedule, debuting March 30–April 1, 2027, with further editions booked there in 2028 and 2029, per KJZZ. "By establishing Phoenix as the long-term home of our flagship North American event, we're creating greater consistency for attendees while building on the tremendous momentum of Arizona's rapidly expanding semiconductor ecosystem," said Joe Stockunas, president of SEMI Americas. The Chronicle reported the move reverses an earlier plan to rotate the show between the two cities — meaning the Bay Area didn't lose a coin flip so much as get written out of the rotation entirely.

Here's the part the city's recovery pitch has to reckon with: the conference is following its industry, and the industry's new capacity isn't here. Trade shows anchor to where the buyers and the plants are, and the semiconductor build-out of the past three years has been in metro Phoenix — TSMC's multi-fab Arizona campus (a commitment the company escalated to $165 billion in March 2025) and Intel's long-running Ocotillo site in Chandler. SEMI credited the strong turnout at Semicon West's first Arizona edition, in 2025, as evidence the audience has already moved. There is no comparable leading-edge fab construction in the nine-county Bay Area to hold the show in place.

San Francisco has spent two years selling a downtown comeback story — falling crime, returning office workers, a fatter AI-company roster, a rebuilding convention calendar. Losing a marquee, recurring booking cuts against that narrative in a way a one-off festival doesn't: this is a repeat tenant with a five-decade history choosing to leave. The event historically drew roughly 11,000 attendees and about $18 million in annual economic impact to downtown SF, per figures cited by Yahoo News; Phoenix projects some $10 million in direct spending and 16,000-plus hotel room nights from its version.

What to watch: whether the October 2026 send-off is treated as a genuine finale or a bargaining chip, and whether SF's convention bureau backfills the Moscone dates with anything of comparable scale. The city can point to AI conferences filling ballrooms downtown; it can't point to a chip fab. That gap is why this one left.