Donald Trump is making volatility great again. If the reaction to the U.S. President-elect's first press conference is anything to go by, we are in for big swings in currency markets this year.

One-week implied volatility on the euro-dollar, a measure of the cost of options to protect against swings in the currency, surged the most in a month after Trump's press conference last week. And that came on the back of no real policy news. A dollar index dropped as much as 2 percent in two days.

With Trump's policy agenda still uncertain, the theme of greater fiscal stimulus and higher inflation that have driven up the dollar and U.S. Treasury yields is not a one-way bet. Divided market positioning means surprises either way on Trump's promises will add to price swings, causing an increase in hedging costs for investors.