The Move

On Monday, October 5, the Brazilian market had its best day since 2020. The Ibovespa rose 7.7% and closed above 200,000 points for the first time, the dollar fell 4%, and Brazil's ETF in New York rose 12.5%. The trigger was the first round, in which Flávio Bolsonaro led Lula 47 to 45, against polls showing Lula ahead.

The figure that matters for payments becomes clearer in dollars, against that ETF. On that day, XP rose 31%, PagSeguro and StoneCo 21%, and Inter 20%. Nu rose 13%, in line with the ETF.

Then the index stalled, and the fintechs did not. Through Friday, October 9, the ETF gained another 1%; XP, 14%; Inter, 17%; StoneCo, 8%. On the week, XP +50% and Inter +40%, against 14% for the ETF. Politics explains Monday. It does not explain the rest of the week.

The Curve, Not the Candidate

On the same Monday, the long end of the yield curve fell more than one percentage point; the DI contract for January 2035 dropped 133 basis points, to around 12.8%. The market read the lead and a more rightward Congress as a path to fiscal adjustment and lower rates, sooner.

My reading is that Brazilian payments companies are exposed to this curve through three channels. The cost of funding follows the Selic, now at 13.75% after five 25-basis-point cuts from its peak of 15%. Credit portfolios, which account for most growth, yield based on that same rate. And valuation depends on profits years out, discounted by it. StoneCo has told investors that each 100 basis points of Selic is worth between R$ 200 million and R$ 250 million of pre-tax profit. A one-point move at the long end reprices all three channels at once.

The exchange rate is a fourth channel: these companies invoice in reals and are traded in dollars.

The Second Week

The rally priced in a result, and this week polls put it in doubt. Quaest, on Wednesday, gave Flávio 51% to 49% of valid votes; Datafolha, on Thursday, also 51% to 49%, against 52% to 48% a week earlier. Both are a statistical tie. Quick approval, in the Senate, of the end of the 6x1 work schedule was read as a victory for Lula's campaign.

The market gave back part of the move. The Ibovespa fell three straight sessions and closed Thursday at 204,324 points, 2.3% below Friday's record; the dollar returned to R$ 5.09; the January 2035 DI rose 21 basis points on Thursday, to 12.87%. The fintechs fell more. From Friday through Wednesday, before Thursday's decline, Inter fell 9%, StoneCo 8%, Nu 7%, and XP 5%, against 2% for the ETF.

It is the same lever, in reverse. A stock that rises several times more than the index when the curve falls also falls several times more when it rises.

What Needs to Go Right

Three things, in this order. The second round on October 25 needs to come out as the market assumed. The fiscal signal that follows needs to be credible enough to hold the curve where it got to. And the Selic needs to follow, which, by the numbers in Focus itself, is more likely in 2027 than in 2026.

If all three hold, the difference is justified. If the first fails, it closes as it opened, in a morning. The second week showed that doubt alone is enough to begin it.

What to Watch

The polls through October 25, the only numbers capable of moving the curve before the vote. The dollar in relation to R$ 5. And the Copom on November 4, ten days after the second round: by then, nothing has changed in the Selic, only the expectation.

Where payments companies operate credit financed near the base rate, their shares are a bet on rates with a fintech face. Brazil showed what this looks like when the curve moves, in both directions.