(Bloomberg) -- The dollar is heading for its best week in a month as investors return to the traditional haven amid heightened geopolitical tensions. One-week options positioning turned the most dollar-positive in a month, a sign that traders are paying up for protection ahead of next week's Federal Reserve meeting. Beneath the geopolitical headlines, US interest-rate volatility has re-emerged as a key driver of foreign-exchange markets. "US rate volatility is rising and moving to front of mind for the market," said BNY strategist David Tam. The yield on 10-year Treasuries touched 4.7117% Friday, the highest since mid-January, and traders now assign a one-in-three probability for a quarter-point Fed rate increase next week.