Waymo and Robotaxi Expansion 2026

Two exchanges price the same eleven Waymo cities. One has forty-five times the volume; the other has the tighter market.

Kalshi's KXWAYMOCITY-26DEC turned $170,900 today against Polymarket's $3,806 on the same question—and where Kalshi quotes Denver 70 bid / 98 ask, a twenty-eight point spread, Polymarket quotes it 81 / 91. The venue doing a fortieth of the business is making the better price.

Where both books are liquid they agree almost exactly. San Diego prices 90.0% on both. Tampa 94.0% against 92.2%. Sacramento 54.0% against 51.5%. Denver 84.0% against 86.0%. Four cities, four agreements inside two points.

Where they are thin they do not agree at all. London prices 12.0% on Kalshi and 37.5% on Polymarket—where it is quoted 11 bid / 64 ask. Portland is 21.5% against 10.0%. Seattle is quoted 4 / 68 on Kalshi.

Four legs on Polymarket's board carry slugs that name a different city than the leg's own title. The market displayed as Denver, CO has the slug will-waymo-launch-in-las-vegas-...; Boston, MA has ...-washington-dc-...; Charlotte, NC has ...-dallas-...; Chicago, IL has ...-denver-.... The whole how many cities board has the same problem in the other direction—every slug reads on-june-30 under an event titled by December 31. Which label governs settlement is not something a reader can tell from the page, and it is worth knowing before trading either board.

59% of Kalshi's day went through one city. Denver took $100,113 at a midpoint of 84% derived from that twenty-eight-point spread.

And a settled contract is sitting at 50.0% again. On Kalshi's robotaxi-states board, Florida has resolved Yes and is quoted 0 bid / $1.00 ask, holding $5,801—24% of that book's open interest.

The same eleven-city question on two exchanges, side by side.

Kalshi's board turns $170,900 on $204,496 held. Denver 84.0%, Tampa 94.0%, San Diego 90.0%, Las Vegas 85.5%, Sacramento 54.0%, Detroit 37.0%, Seattle 36.0%, Portland 21.5%, London 12.0%, Washington DC 7.5%.

Polymarket's board turns $3,806 on $6,871 held. San Diego 90.0%, Tampa 92.2%, Denver 86.0%, Sacramento 51.5%, Charlotte 39.0%, Chicago 38.0%, London 37.5%, New York 21.5%, Minneapolis 16.0%, Portland 10.0%, Boston 8.0%.

The four cities both books trade agree inside two points. The rest do not. London is 25.5 points apart, Portland 11.5. Both of those are quoted with spreads wider than the disagreement, so the gap is a quoting artefact more than a difference of opinion—but the numbers a reader sees are 12% and 37.5%.

The city taking 59% of the book, and the one both venues price identically.

Denver took $100,113 of Kalshi's $170,900—almost three fifths of the day—and holds $106,630. Its midpoint of 84.0% comes from a 70 bid against a 98 ask. Polymarket prices the same city at 86.0% on an 81/91 quote and traded $637.

San Diego is the control. Both exchanges mark it at exactly 90.0%, Kalshi on an 85/95 quote and Polymarket on 88/92. It is the second-busiest leg on both boards. When these books are actually contested they land in the same place; the disagreements are all in the corners nobody trades.

How many cities, and which states—the two count boards.

Polymarket's count board sums to 105.8% and centres on 16–19 cities at 51.5%, with 12–15 at 37.05%, 20–23 at 9.5%, 24–27 at 3.05%, fewer than 12 at 2.9% and 32-plus at 1.2%. Every one of its market slugs reads on-june-30 beneath an event titled by December 31, so the board's own naming disagrees with its own question.

Kalshi's robotaxi-states board has a resolved leg at 50.0%. Florida has settled Yes and is quoted 0 bid / $1.00 ask, holding $5,801 of the book's $23,885—24% of the open interest on a question already answered. Nevada prices 86.5%, Arizona 76.5%, Georgia 37.0%.

And California prices 9.0%—while holding $9,783, the deepest position in the book. Whatever definition of "offered to" that contract uses, it is not the one a reader would assume of a state where robotaxis already carry passengers. Read the rules before the price.

Manifold is the third venue, and it asks the questions the other two do not.

Waymo expanding into Marin County by year end prices 54.7% on $2,923—the only contract anywhere in this catalog on a specific service-area extension rather than a whole city.

And Manifold is the only place Tesla's robotaxi fleet is priced at all. Its ladder is cleanly monotone: at least 100 vehicles at 91.3%, 500 at 69.1%, 1,000 at 32.0%, 10,000 at 3.4%, 100,000 at 2.4%, a million at 1.0%. It has traded nothing, so those are quotes rather than prices—but the shape is coherent, which is more than the Kalshi states board manages.

Polymarket's Tesla launches robotaxis in California by December 31 prices the same story as a single binary and turned $29.

• Kalshi turns forty-five times Polymarket's volume on the same board and quotes it four times wider. $170,900 against $3,806; Denver 70/98 against 81/91. The thin venue is making the better market.
• Where both are liquid they agree inside two points. San Diego is 90.0% on both. Tampa, Denver and Sacramento are all within two.
• Where they are thin they are 25 points apart. London 12.0% against 37.5%, on quotes of 7/17 and 11/64.
• Four Polymarket legs carry slugs naming a different city than their title, and every leg of the count board reads on-june-30 under a December question. Check the rules text before trading either board—the page cannot tell you which label settles.
• 59% of Kalshi's day went through Denver alone, $100,113 at a midpoint drawn from a 28-point spread.
• A settled Florida contract holds 24% of the robotaxi-states book at 50.0%, quoted 0 bid / $1.00 ask.
• California prices 9.0% and holds the deepest position in that book. The contract's definition is doing work the price does not explain.
• Manifold is the only venue pricing Tesla's fleet, and its ladder—91.3% / 69.1% / 32.0% / 3.4%—is the most coherent thing on this page, on zero volume.
• All three city boards settle in the first week of January. Watch whether Polymarket's slug mismatches are corrected before then.