The Swiss franc has jumped to its highest level against the dollar since 2015, when Switzerland’s central bank abandoned its policy to contain currency strength.

The currency reached CHF0.8551 per dollar on Friday, its strongest level in almost nine years. Versus the euro, the franc rose as high as CHF0.94112.

The franc is outperforming all its G10 currency peers this year, bolstered by the view that the Swiss National Bank’s (SNB) preference for a stronger domestic currency will keep it afloat. ...