The European Central Bank bought a record 44 billion euros ($47.64 billion) worth of bonds across its stimulus programs last week, but still failed to rein in borrowing costs for Italy and other indebted countries, ECB data showed on Monday.
The ECB plans to buy at least 1.1 trillion euros of bonds this year to help eurozone governments, companies and households navigate the coronavirus pandemic and lockdown measures that are pummelling economic activity.
But its unprecedented efforts have failed to pay off so far.
Despite the biggest weekly purchases on record, including at least 7.1 billion euros of public sector debt, yields on Greek, Italian, Portuguese and Spanish benchmark bonds all rose last week.
This showed private investors were dumping that paper despite the ECB's pledge to keep buying it for as long as needed and to fight any sign of "fragmentation" -- code for surging risk premiums for more indebted countries.
The ECB has yet to publish an asset breakdown of its Pandemic Emergency Purchase Program (PEPP), which currently accounts for most of its purchases.