According to the press, both institutions now face the threat of deposit withdrawals although the scale is unknown. The underperformance of Polish government bonds and the zloty, as well as asset swaps widening in the last week, signal that both institutions reduced liquid assets (effectively POLGBs holdings) to fight liquidity constraints.
According to publicly available balance sheets of both institutions, at the end of 2Q18, the banks had in their books about PLN9 billion of securities ‘ready to sell’ (presumably the majority was POLGBs). The institutions have probably already reduced their debt holdings, so further stress in POLGBs is likely to be limited. In the case of continued deposit withdrawals, they may rely on (costly) central bank aid (i.e. refinancing credit) - the National Bank of Poland and the macro-prudential committee have already pledged support if needed.