Kamala Harris' Odds of Winning Democratic Nomination Surge on Polymarket

Vice president Kamala Harris' odds of becoming the Democratic nominee for president this year more than quadrupled on Tuesday, according to traders on Polymarket, the crypto-based prediction market platform that's seen torrid growth in an election year.

"Yes" shares in a contract asking whether she will get the nod traded as high as 31 cents in the afternoon New York time, indicating the market saw a 31% chance it will happen, up from 7% earlier in the day. The shares retraced some gains and recently traded at 23 cents.

Each share pays out $1 (in USDC, a stablecoin, or cryptocurrency pegged to the U.S. dollar) if the prediction comes true, and zero if not.

Officially, President Joe Biden is still the presumptive Democratic nominee. But many supporters are calling on him to step aside, and some of them want Harris to step up following her boss's doddering performance at last week's debate with former commander-in-chief and almost-certain Republican standard-bearer Donald J. Trump.

"We should do everything we can to bolster her, whether it’s in second place or the top of the ticket," Rep. James Clyburn, D-S.C, said on television Tuesday.

A Newsweek op-ed by former Congressman Tim Ryan, the first presidential candidate to endorse Biden in 2020, was more blunt: "Kamala Harris Should Be the Democratic Nominee for President in 2024." An analysis by The Wall Street Journal called Harris "Biden’s Likeliest Replacement."

The trend was similar Tuesday on PredictIt, a more traditional prediction market platform where bets are settled in dollars rather than crypto. "Yes" shares for Harris there more than doubled to 35 cents. PredictIt's volume on the question of who will win the Democratic nomination totals $31 million, dwarfed by Polymarket at $75 million.

Under a settlement with the Commodity Futures Trading Commission, Polymarket is barred from doing business in the U.S., whereas PredictIt is allowed to operate in the country under a regulatory exemption.

Tuesday was Polymarket's fifth-largest volume day in its four-year history, with $5.7 million in trading, according to Dune Analytics data. June was the first month Polymarket saw more than $100 million in volume.

Its largest contract by far, with $211 million in bets, asks who will win the U.S. presidency in November. Trump remains the favorite, with a 66% chance of victory.

Meanwhile, KAMA, a meme coin named after the vice president, rallied Tuesday, more than doubling in price over 24 hours to $0.007815.