http://www.swissinfo.ch/eng/swiss_news/Unclaimed_nest_eggs_lie_in_wait.html?cid=37799962

Every year, provident funds lose track of tens of thousands of former policy holders - half of them foreign - who would be entitled to pension money. Billions of francs are waiting to be claimed.

Many former policy holders simply disappear into thin air, with no forwarding address. It is estimated that a total of around CHF5 billion ($5.5 billion) remains unclaimed, accumulated in Swiss pension funds.
 
This generally occurs when someone changes employer – even if, in theory, it shouldn’t be possible. In fact, the occupational pensions law states each policy holder is entitled to a free movement service, in other words their pension fund capital is paid on to the provident fund of their new employer.
 
If the policy holder doesn’t find a new employer straightaway, the accumulated assets ought to be deposited in a blocked account with the Substitute Occupational Benefit Institution (SOBI) (see box) or with a bank or insurance company.
 
These assets should remain there until the policy holder asks for the transfer to a new pension fund or until payment at retirement age...