Mohsin Issa says he and his co-owner brother are "here for the long haul", despite Asda's £5bn debt.
This is the fourth rise in two years for first class stamps and the second class cost will rise too.
The lawsuit accuses the firm of abandoning its founding principle of benefiting humanity.
Lawyers for sub-postmasters say some investigators may have conspired to pervert the course of justice.
There will only ever be 21 million bitcoins, and US financial giants are buying up thousands.