Colombia's dollar bonds tumbled across the curve Thursday as markets reacted to a new poll showing leftist Senator Iván Cepeda with a commanding lead in the presidential race. The Colombian peso led emerging-market currency losses, reflecting investor concerns about potential policy shifts under a left-leaning government.

Cepeda's rise in the polls has unsettled investors who fear his administration could pursue more interventionist economic policies. The bond selloff was broad-based, with yields rising across different maturities as traders priced in higher political risk. Currency traders pushed the peso lower, making it the worst-performing emerging market currency on the day.

The market reaction underscores how political uncertainty can quickly impact Colombia's financial markets. Investors are particularly sensitive to the possibility of changes in fiscal policy, energy sector regulation, and relations with international partners under a leftist administration. The polling data suggests Cepeda could secure a decisive victory, potentially leading to significant policy changes.