What happens to the Jewish businesses? How do Jewish people earn money to live at this time?

Jewish businesses are taken over by the Nazis. Vladek and others exist on an underground black market economy. Vladek continues to conduct black market business until a friend of Anja's father is executed for selling goods without coupons and is left to hang for days as a warning to others. Vladek had often done business with the man, and he is terrified to go outside for a few days. Vladek begins dealing in gold and jewelry, which is easier to hide than clothing but still dangerous, and also does some business selling food. Business is still dangerous, though. On one occasion, Vladek is delivering a sack full of illegal sugar when he is stopped by a German patrol. Rather than run, he lies and tells them that he owns a grocery store and that he is carrying the sugar there, legally. He makes his delivery as planned, with the guards watching.