The Swiss National Bank (SNB) bought foreign currencies worth 2.3 billion francs last year.

The central bank has waged interventions from time to time over the past decade as it seeks to stem appreciation pressure on the currency, but provides few details on such action and only lists a total in its annual report.

The tally for 2018 is the smallest since 2013. Last year the franc briefly fell as low as 1.20 per euro on waning risk aversion in April, though later reversed most of that slide.

The SNB is likely to affirm its commitment to interventions at its policy announcement later on Thursday.