Los Angeles Mayor Karen Bass is getting a major Election Day boost — with her odds of keeping City Hall exploding from 57.6% to 75% in just three hours on prediction market Kalshi.

Bass’ chances of reelection jumped more than 21 percentage points between 1 p.m. and 4:30 p.m. Tuesday, a stunning afternoon swing in a race that recent polling showed was deadlocked.

The incumbent mayor is facing Socialist challenger Nithya Raman in a heated contest, with both candidates polling at 40% in late October and another 20% of voters still undecided.

The sudden market shift comes as traders monitor Election Day turnout, with precinct-level participation potentially offering clues about which candidate is gaining ground.

Heavy turnout in liberal strongholds could favor Raman, while stronger participation among older, establishment voters could benefit Bass.

In a race this tight, even small pieces of new information can send prediction-market contracts swinging.

Still, the figures do not establish what triggered Bass’ afternoon surge — and Kalshi’s 79% reading is a market-implied probability, not a declaration of victory.

Los Angeles County began mailing ballots to active registered voters Oct. 5, while hundreds of vote centers opened Tuesday at 7 a.m. and are scheduled to close at 8 p.m. PST.

Federal election monitors are on the ground in the Los Angeles area as voters head to the polls, prompting California to launch its own platoon of observers to keep an eye on the feds.

The US Justice Department says it’s part of a nationwide effort to ensure election integrity, but the move is drawing criticism from Governor Gavin Newsom and LA Mayor Karen Bass, who say it’s an attempt to intimidate voters.

Initial results are expected after polls close, but the close contest could mean a lengthy wait before a definitive winner is known — potentially days or even weeks.