se leggi il mio link lo dice ,è una regola del prospetto,che trovi sul loro sito
The increase of nominal values results from the exercise of the right
provided in the Conditions of Issue of the bonds (Section 3 (4)) to pay
accrued interests together with the principal on maturity date.
Consequently, margin will be increased retroactively for the respective
interest period from June 30 to September 29, 2016, to 10% p. a. plus the
base interest rate 3-month EURIBOR of at least 1% p. a. As at September 30,
2016, the nominal values of the bonds will increase by the respective
interest amount accrued by September 29, 2016.