To add to what has already been said, the obsessive rocking on a horse that is, in reality, going nowhere presents an interesting parallel to humankind's search for wealth. The rocking horse is stationary. It sits in one place and does not move in spite of the fact that he keeps on rocking. This is a lot like life in that we often pursue wealth incessantly with no clear direction for where we are going. It is the vicious cycle of questing after possessions that, essentially, are meaningless to us after we are dead. The family gets the money, and the father clearly values the money more than the son, but in the end when we die we can't take material wealth with us to the grave (well, we can, but what is the point?). Therefore, the story asks a critical question - how important is wealth? Is money truly as valuable as we make it out to be? And, in the end, which is more important: money or a life well-lived in pursuit of something more tangible than spinning one's wheels in place for all eternity?
The quest for money in "The Rocking-Horse Winner" is portaryed as tragic irony because Paul ends up giving his life for his family. It is the desire for more money that motivates all of the characters in the story. Perhaps the most blatant evidence of the family’s obsession with riches appears in Uncle Oscar’s attempt to console his sister after her son’s death: “My God, Hester, you’re eighty-odd thousand to the good and a poor devil of a son to the bad” (244)—as if he were enumerating her as assets and liabilities on an imaginary balance sheet. Paul’s frenzied pursuit of money differs from the greed of the others in that he wants wealth not for himself but for his mother. Clearly he hopes that, by being “luckier” than his father, he will win his mother’s love and attention. In the end, he gets neither.