I just came back from the Vipers Nest Questline (I was away from Rattay for 2 - 3 Days) and every trader resettet their wealth. The Armourer was at 20k, now hes back to 2k, the Weapon Smith was at ~11k, now hes at 1,7k.
They prolly know it is foolish to keep a huge sum like this at home and sent it to the bank or to the Templar.
Maybe the taxman payed a visit, or Henry has competition as the king of thieves.
and now, a few days later, both have 0, clearly bugged
my impression (perhaps false) is that you have to keep the pump primed or else their groschen pool disappears
Same impression as frelmedieval.