What's peculiar here is that the Finanzagentur retains a stock of bonds which then uses for secondary market purchases, but (if we are to believe them) not as a market maker and as a price-taker. The Finanzagentur could well engage in limited yield manipulations in the secondary market, which would basically mean the federal government would be meddling in monetary policy. Of course they would never dream of doing such a thing. What they do say is that there is a "Federal Government [own Bond liquidity] Management", which could be construed also as meddling in monetary policy.

To err is of course human. But to mess things up spectacularly, we need an elite — Yanis Varoufakis