The ECB has started to provide some hints concerning the volume of its balance sheet expansion plan announced last week. Markets are concerned that purchases of asset-backed securities could potentially lead to some troubles in the Euro zone, particularly as securities of periphery countries will not be excluded from the transactions, despite their rating being below investment grade. However, the ECB Vice President Vitor Constancio reassured that the ECB will not buy "junk securities with a high risk of default". He said that 1 trillion euros of asset-backed securities and covered bonds are eligible for purchase.