Shallow and selfish, Uncle Oscar of "The Rocking Horse Winner" does nothing to help his sister Hester come out of her financial predicament, although he has inherited the family fortune. When he learns that Paul earns money through gambling, he greedily takes advantage of the boy by betting on the winners that Paul selects: "That's right, son!...Don't you stop till you get there," he tells Paul as he slides off his childhood toy, the rocking horse.
And, even though Uncle Oscar is aware that Paul engages in the bizarre activity of obsessively rocking on a toy that he has outgrown, throwing himself into a trance, he does not say anything to Paul's mother, nor does he caution Paul against the dangers of gambling. Instead, he arranges for a lawyer to send Hester a sum of money each month, disguising its origin. This behavior of Oscar's reinforces the motif of preoccupation with money and material possessions over spiritual vales.
Somewhat ironically, however, it is Uncle Oscar who does finally realize the importance of responsibility and spiritual values. For, as Paul lies dead, it is Oscar who tells his sister,
My God, Hester, you're eighty-odd thousand to the good, and a poor devil of a son to the bad. But, poor devil, poor devil, he's best gone out of a life where he rides his rocking-horse to find a winner.