Why are Brazil’s presidential polls so different from one another?

Brazil's presidential polls
Brazil’s presidential polls are at the center of a controversy

At the beginning of June, a presidential poll by DataPoder360 – a company created by news website Poder360 –  created havoc in financial markets. It showed the election front-runners to be two candidates dreaded by investors: the far-right Jair Bolsonaro, who had a comfortable lead with 25 percent of voting intentions, and the center-left Ciro Gomes, with 12 percent. São Paulo’s stock market crashed by 6 percent, and the Brazilian Real lost 2 percent against the U.S. Dollar, which closed June 7 at BRL 3.95.