The fund designed to shield taxpayers from future banking crises in the euro zone totaled €24.9 billion at the end of June.
This is close to half the maximum size it is supposed to reach in 2023, the institution in charge of it said today.
Euro zone countries created the fund, and the Single Resolution Board that runs it, in 2014 to finance the winding down of failed banks as a means of better managing bank risk.
It is being financed by banks themselves, with contributions due to reach 1% of all covered deposits in 2023.
In 2014 the European Commission estimated that as equivalent to around €55 billion.
The board said that, as of 30 June, it had collected €7.5 billion from 3,315 institutions in annual contributions and the fund held €24.9 billion in total.
Euro zone finance ministers agreed in June that their bailout fund should be able to lend the bank resolution fund up to €60 billion in the event of a major crisis.
Money from the bank fund may be used to guarantee the assets or liabilities of a bank under resolution, lend to that bank, buy its assets or pay shareholders or creditors.
But it can not be used directly cover losses or to recapitalise a bank.