To say the least, the just completed trading week was an interesting one for Brazilian stocks and the related exchange traded funds.

Ahead of Sunday’s runoff election between between President Dilma Rousseff and challenger Aecio Neves, Brazil ETFs, including the group’s kingpin, the iShares MSCI Brazil Capped ETF (NYSEArca: EWZ), were all over the place this week.

On Monday, EWZ and the Market Vectors Brazil Small-Cap ETF (NYSEArca: BRF) were two of the worst-performing non-leveraged ETFs as polls showed a statistical dead heat between Rousseff and Neves. EWZ and BRF would repeat that offense Thursday as both ETFs tumbled following the release of polls that showed Rousseff well ahead of the upstart Neves. [Brazil ETFs Volatile Ahead of Election]

Thursday’s tumble could have easily led investors to the conclusion that a Rousseff victory is a foregone conclusion, but there appears to be more to the story. At the very least, EWZ’s options market says traders are split on the Rousseff/Neves outcome.

On Thursday, the number outstanding options contracts in EWZ reached a record 5.6 million with traders holding roughly the same number of calls and puts, report Julia Leite and Denyse Godoy for Bloomberg.

That increased options gave way to EWZ surging 4.3% Friday on heavy volume while BRF soared 5% on more than double the average turnover.

“EWZ flows as an ETF itself continue to interest us heading into the country’s elections, as close to $700 million has entered the fund in recent sessions via creation activity,” said StreetOne Financial Vice President Paul Weisbruch in an interview with ETF Trends. “This represents more than 10% of the assets under management in the fund, which debuted way back in the summer of 2000. In spite of weak performance year to date (EWZ traded with a $40 handle yesterday for the first time since March this year), this has not stopped the fund from pulling in an impressive amount of new assets via creations.”

Robust activity in EWZ’s underlying should not come as a surprise. Entering Monday, EWZ, the largest and most heavily Brazil ETF, had “a 30-day implied volatility of 70%. This means that the options market is pricing in a move of plus or minus 20% on EWZ within the next month,” reports Mike Zaccardi for See It Market. [More Volatility for Brazil ETFs]

EWZ also has one of the most active and liquid options markets of any single-country emerging markets ETFs and as measured by standard deviation, the ETF is more than 1,100 basis points more volatile than the iShares MSCI Emerging Markets ETF (NYSEArca: EEM).