Daily Market Mispricings: 2 Election Events Where We Disagree With Polymarket — May 21, 2026

TL;DRNaly’s sharpest May 21, 2026 election disagreement is Colombia: Polymarket prices Iván Cepeda at 83c to win outright in round one, while we mark that same YES contract at 10c fair value because leading polls still sit well below the 50% threshold. We also flip Peru, where Roberto Sánchez looks closer to a coin flip than a 22c long shot.

Prediction markets are useful because they compress a lot of information quickly. They also make systematic mistakes when traders anchor on who is leading instead of what a contract actually requires to resolve. Today’s two biggest election mispricings are both answer flips: one market seems to confuse first-place polling with an outright first-round majority, while the other still underprices coalition math in a runoff.

Key Takeaways

Colombia looks like a classic threshold error: leading the first round is not the same as clearing 50% plus one.

Peru looks like a coalition error: a weak first-round base can still become a live runoff majority when most voters backed someone else.

In both markets, Naly disagrees on the final answer itself, not just on confidence.

The next catalysts are late polling, endorsement flow, undecided-voter movement, and any sign of turnout asymmetry.

2 Mispricings at a Glance

Event Snapshot

Will Iván Cepeda Castro win the 1st round of the 2026 Colombian presidential election?

YES Resolves May 31, 2026 Open 92% confidence

Polymarket Top Answer YES

Naly Top Answer NO

Max Payout if Correct +17c

0c 50c $1.00

Polymarket Naly

Why we disagree: The market appears to price Cepeda as if a polling lead is close to an outright majority, but recent reporting still places him materially below 50% with a large undecided bloc and a runoff path as the base case.

Event Snapshot

Will Roberto Sánchez Palomino win the 2026 Peruvian presidential election?

YES Resolves June 7, 2026 Open 86% confidence

Polymarket Top Answer NO

Naly Top Answer YES

Max Payout if Correct +78c

0c 50c $1.00

Polymarket Naly

Why we disagree: The market still prices Sánchez like a first-round outsider, but the runoff is official, over 70% of first-round voters backed someone else, and recent reporting points to either a dead heat or only a narrow Keiko edge.

How to read this: Polymarket Top Answer and Naly Top Answer show the final answer each side sees as most likely. Max Payout if Correct shows the gross upside from the current quote to the $1 settlement if the selected contract side wins. The horizontal graph still shows where that selected side sits on a 0c to $1 range for Polymarket versus Naly.

Event 1

Will Iván Cepeda Castro win the 1st round of the 2026 Colombian presidential election?

PoliticsContract · YESResolves May 31, 2026Open92% confidence

+17c

Max Payout if Correct

Polymarket Top Answer YES

Naly Top Answer NO
Trade on Polymarket →

This quoted market price refers to the YES side: buying YES at 83c means paying 83 cents now for a contract that pays $1 only if Cepeda wins outright in the first round, so it also implies roughly an 83% market probability. Our 10% estimate translates to a 10c fair price on that same YES contract. That is different from max payout if correct, which is only 17c on YES at today’s entry price; the fair-value edge is the much larger gap between 83c market and 10c fair value. This is a full answer flip: Polymarket’s top answer is YES, ours is NO.

Causal Chain

Cause Cepeda’s polling lead makes him the likeliest first-place finisher, but not an outright majority winner.

↓

Effect A fragmented right and a still-large undecided pool make it easier to force a runoff than to close the election in one round.

↓

Projection Unless late polling shows a real break above the low-40s into majority territory, the median path is Cepeda first on May 31 and a second round on June 21.

Key Factors

| Factor
▲ | Colombia requires more than 50% of valid votes to avoid a runoff, which is a much stricter bar than simply leading the field.
▲ | Recent reporting still frames the main fight as who joins Cepeda in the second round, not whether there will be a second round.
▲ | EL PAÍS reported on May 21 that undecided voters may still represent about 28% of electors, which is too large a residual bloc to justify near-certainty on an outright first-round win.
▲ | Recent polling cited by Rio Times had Cepeda between roughly the high 30s and mid-40s, still short of the legal threshold.
▲ | AtlasIntel reporting from May 15 showed Abelardo de la Espriella closing the gap, which cuts against a clean majority-closing story.

Bayesian Calculation

Base rate: 83% market-implied YES, but we treat that as overstated because it seems anchored to first-place status rather than the runoff rule.

Positive update: Cepeda is consistently the frontrunner and benefits from a divided opposition.

Negative update: public reporting still places him below 50%, with large undecideds and a competitive race for the second runoff slot.

Naly estimate: 10% YES, 90% NO.

Alternative explanation: The market may be assuming a late bandwagon effect in which undecided left-leaning and anti-right voters break heavily toward Cepeda once the field compresses in the final week. If that surge materializes, today’s price would look less extreme.

What Would Make Us Wrong

We would be wrong if final weekend polls show Cepeda actually crossing the majority line, or if turnout composition heavily favors his coalition while right-wing voters remain split or underperform. A sudden collapse by the second-place challenger would also matter.

Fresh Checks

EL PAÍS: undecided voters could still decide who joins Cepeda in the runoff

El Universal: AtlasIntel shows Cepeda at 37.6% and De la Espriella at 32.9%

EL PAÍS: Cepeda’s platform coverage as the first-round frontrunner

Rio Times: no major poll has Cepeda above the majority threshold

Event 2

Will Roberto Sánchez Palomino win the 2026 Peruvian presidential election?

PoliticsContract · YESResolves June 7, 2026Open86% confidence

+78c

Max Payout if Correct

Polymarket Top Answer NO

Naly Top Answer YES
Trade on Polymarket →

This quoted market price refers to the YES side: buying YES at 22c means paying 22 cents for a $1 binary contract if Sánchez wins on June 7, so the market is implying roughly a 22% chance. Our 53% estimate maps to a 53c fair price on that same YES contract. That fair value is separate from max payout if correct, which is 78c on YES at today’s entry price. This is another answer flip: Polymarket’s top answer is NO, while ours is YES.

Causal Chain

Cause Sánchez’s weak first-round share understates his runoff viability because June 7 is now a head-to-head coalition contest, not a 35-candidate field.

↓

Effect Since more than 70% of voters backed someone else in round one, the decisive question is where anti-Fujimori, protest, and provincial votes consolidate.

↓

Projection If Sánchez captures enough of the anti-establishment and anti-Fujimori bloc, a nominal underdog in round one can become a narrow favorite in the runoff.

Key Factors

| Factor
▲ | AP confirmed the runoff is official for June 7 and noted that more than 70% of first-round voters chose neither finalist.
▲ | Reuters reported an April 26 Ipsos runoff poll showing Fujimori and Sánchez tied at 38%-38%.
▲ | AS/COA highlighted that the two finalists combined for only about 29% in round one, implying an unusually large reallocation pool still in play.
▲ | Sánchez benefits from anti-Fujimori tactical consolidation because Keiko Fujimori remains a polarizing repeat runoff figure.
▲ | The market may still be anchoring on Fujimori’s first-round lead and Sánchez’s association with Pedro Castillo, but that does not automatically decide a two-candidate runoff.
▲ | Even recent reporting of a narrow Keiko polling edge still looks much closer to a coin flip than a 22% chance for Sánchez.

Bayesian Calculation

Base rate: 22% market-implied YES, which we view as too low once the runoff field is fixed.

Positive update: the runoff is confirmed, earlier runoff polling showed a dead heat, and coalition math favors large vote transfers from non-Fujimori voters.

Negative update: Fujimori finished first in round one, leads some recent snapshots, and Sánchez carries ideological and legal baggage that can cap centrist support.

Naly estimate: 53% YES, 47% NO.

Alternative explanation: The market may be discounting private polling that shows a stronger late break to Keiko in Lima and among security-focused voters. If undecided moderates choose order over change, Sánchez’s provincial coalition could stall below 50%.

What Would Make Us Wrong

We would be wrong if late public polls showing a Keiko edge are the start of a broader late-campaign consolidation, or if Sánchez fails to unify the anti-Fujimori electorate. A clean law-and-order narrative that dominates the closing week would also hurt this call.

Fresh Checks

AP: Peru’s electoral board confirms the June 7 runoff between Fujimori and Sánchez

Reuters: official results show Sánchez in the runoff and cite an earlier 38-38 Ipsos tie

AS/COA: the two finalists combined for only 29% in the first round

Infobae: latest Ipsos snapshot shows Keiko ahead 39% to 35%

Conclusion

The sharp watchpoints ahead are straightforward. In Colombia, the key question is whether any final poll actually shows Cepeda near or above 50%, not whether he still leads. In Peru, the key catalysts are endorsement flow, provincial turnout, Lima margin compression, and whether anti-Fujimori consolidation outweighs Sánchez’s baggage. Those are the variables most likely to move these two answer flips before resolution.

Methodology

Our election mispricing method is the same one we use in finance roundups: start with the contract’s exact resolution rule, translate the current cents price into an implied probability on that same side, then rebuild fair value from causal drivers instead of crowd sentiment. We compare threshold structure, coalition math, turnout asymmetry, late polling behavior, and resolution mechanics against historical base rates and public evidence. Our broader calibration record is tracked at /track-record.

Disclaimer

This article is for information and research purposes only, not investment, legal, or voting advice. Prediction market prices can move quickly, election reporting can be incomplete, and our fair values are probabilistic estimates rather than certainties.