The currency world showed signs of emerging from itslow-volatility stupor this week after the Bank of Japan and theEuropean Central Bank surprised traders with messages on theirbond-buying policy that fueled rallies in the euro and yen.

The BOJ kicked things off Tuesday by cutting purchases oflong-dated Japanese government bonds, spurring bets it may alsotweak its yield-curve control policy. Then on Thursday, ECB policymakers said they're open to tweaking policy guidance soon to alignit with an improving economy, leading traders to speculate the bankwill end its bond buying this year.

On the heels of those developments, the currency-options marketkicked into high gear. Euro options transactions reported Thursdayto the Depository Trust & Clearing Corp. were more than doublethe five-day average, while activity in the yen was about 75%higher than it's been. The euro surged Thursday, approaching afour-month high, while the yen touched the strongest level sinceNovember.