I am confused of how the Swiss National Bank's famous FX interventions are reflected in the change in Sight Deposits.
Against the backdrop of the ECB meeting, it is said that the SNB has taken pressure off the CHF by buying foreign currencies. And it is said that this precise FX intervention is reflected by a +800m CHF change in the Deposit Balance.
Now, I understand the Sight Deposit is simply the reserves banks in Switzerland hold at the SNB. How on earth will FX purchasing action from the SNB reflect on the reserves that some random bank holds at the SNB?
I know this is rather economical than quant, but any help is appreciated