What are Greg's character traits?

In Andrew Clements's novel Lunch Money, the protagonist, Greg, is an industrious, clever, and intelligent young boy. From an early age, he already shows brilliance in money management and entrepreneurship. He is so good with financial matters that he becomes a "banker" for his family. He later comes up with all sorts of business ventures at school, the most successful being graphic novel sales.
His neighbor, Maura, proves to be just as entrepreneurial, except her comic books are better artistically than his are. This conflict reveals Greg's competitive nature and, although the author might not have intended this, his greediness. Greg represents the capitalistic mindset of Americans, which is both a positive and negative trait. On one hand, Greg represents the entrepreneurial spirit and industriousness of American capitalist culture. On the other hand, his qualities show the predatory nature of corporatism and the greediness of ambitious businesspeople.