Options traders have been positioning for volatility to rise in an agribusiness exchange traded fund ahead of quarterly results from top holding Monsanto (NYSE: MON), which reports Wednesday.

There has been a recent trend of “volatility buying” in Market Vectors Agribusiness ETF (NYSEArca: MOO), said Paul Weisbruch at Street One Financial.

“Buyers of straddles have been present (buying both calls and puts simultaneously) in various months, and are positioning for heightened levels of volatility (but uncertain of direction) in the ETF going forward,” he said in a note to subscribers Tuesday.

Monsanto is the ETF’s second-largest holding at 7.3% of the portfolio.

“The index is composed primarily of grain-related agribusiness firms, counting the farmer as a chief customer,” Morningstar writes in an analyst profile of the fund. “The fund owns the world’s largest agribusiness firms, which have had robust growth amid strong demand for grain and other agricultural products from developing nations like China.”