[notathing]

It's weird for such a small country to have such big reserves.

Why not spend some on infrastructure/whatever?

Maybe they use the reserve as some sort of geo-political insurance against possible shocks (whatever those might be)

[internet_user]

It's not weird. They had to print many many CHFs to satisfy the demand for deposits in Switzerland.

They then exchanged them for the USD they now hold.

As for infrastructure/whatever, SNB then went on a massive shopping spree in equities, ~100 billion or so.

They must be the absolutely best managed central bank in the world.