Yesterday's eagerly watched Portuguese bond auction went as well as could be expected, but there is an important question to be asked over how smart it is for the European Central Bank to continue to artificially depress bond yields through its bond buyback programme.

Auction results for yesterday's €1.25bn print of Portuguese government bonds came in at a yield of 6.716% for the 10-year portion, 60 to 70 basis points lower than the last comparable bond. And that comes despite the increased likelihood of Portugal needing some form of emergency assistance from the European Union.