Two Petrobras securities combine for over 12% of EWZ’s weight, not a good thing when considering that with today’s slide, the stock is down more than 30% just this month. Since Rousseff took office on Jan. 1, 2011, Petrobras has been the worst-performing major large-cap oil stock with a U.S. listing. Even BP (NYSE: BP), which had to contend with the aftermath of the largest oil spill in U.S. history, has outperformed its Brazilian rival over that time. [Long Brazil, Short Rousseff Needs to Work]

So sensitive are Brazilian stocks to the specter of Rousseff winning another term that of the 10 worst-performing non-leveraged ETFs Monday, four, including EWZ are Brazil ETFs. Two others, the iShares Latin American 40 ETF (NYSEArca: ILF) and the Guggenheim BRIC ETF (NYSEArca: EEB), have significant Brazil allocations.

iShares MSCI Brazil Capped ETF

Tom Lydon’s clients own shares of EWZ.