There has been a lot of concern recently that banks could decide against calling their AT1s, keeping them outstanding past their call dates.
And with this in mind, investors are starting to price into some securities the idea that they could be around for a long time to come.
There is of course a risk that issuers decide to skip out on using their call options the first time around, with Banco Santander among the top contenders to extend the life of an AT1.
But there is unlikely to be much point in imagining that the first generation of AT1s will end up being perps.
The constant flow of regulatory change in the EU makes it almost unavoidable that banks will be prompted into retiring deals further down the line, regardless of any considerations about the economics of doing so.
There have been growing calls for AT1s to come with higher trigger levels — for example, raising the prospect that use of a 5.125% common equity tier one threshold could eventually be outlawed in Europe.
And the UK’s scheduled departure from the EU means that member states may end up losing their grip on swathes of AT1s written under English law — something that could be rectified using grandfathering arrangements for older deals.
Despite having been around for only about five years, the AT1 market is already starting to look a bit rusty.
Investors worried about pricing outstanding bonds to perpetuity should consider that the asset class could already be in line for a clear-out.