If the new pension fund is not known or did not yet exist at the time of termination, the pension assets are usually transferred to the LOB Guarantee Fund. The state institution currently manages over 80,000 vested benefits accounts with a total of around 2.5 billion Swiss francs, which the insured persons do not know belong to them.
You can find out whether you have any pension fund balance from previous employment relationships by asking the LOB Guarantee Fund. If this inquiry is unsuccessful, you can initiate a search request with the 2nd Pillar central office.
Such requests make sense especially if you have had many, and rather short, employment relationships.