Pip assumes his fortune comes from Miss Havisham for several reasons. First, she is the only one he knows that is wealthy enough to give him such a large fortune. Second, he recognizes Mr. Jaggers from Miss Havisham's house. Third, he recognizes Matthew Pocket's name as the man that will stand at Miss Havisham's head when she is laid to rest. Later, when Herbert Pocket says that he was at Miss Havisham's because she was considering giving him an inheritance, but that she didn't like him, it confirms to Pip that Miss Havisham must be his benefactor. His hope is that Miss Havisham is making him into a gentleman so that he can marry Estella.