From the IB options desk:

EFA – iShares MSCI EAFE Index ETF – Shares of the exchange traded fund representing stocks from Europe, Australasia, and the Far East have come off slightly today to stand less than 0.25% lower at $55.78. Perhaps fearing further bearish movement in the stock, investors coveted approximately 25,000 puts at the October 53 strike for an average premium of 73 cents apiece. Traders picking up the put options may currently hold long positions in the underlying stock meaning a 6% decline for shares of the EFA would be protected by put option exposure and that would kick in beneath the breakeven price of $52.27.

Source: IB