In the tradition of the eighteenth century novel and theater, most of the character names share a similarity in that they tell us something about the nature of the person in question.
Gradgrind, for example, is a harsh name with repeated guttural "gr" sounds, and it reflects the grinding quality of Mr. Gradgrind's emphasis on facts and figures as the only things that count in the world. This philosophy, unfortunately, is learned by the Gradgrind children, who live up to their names, and it causes them to suffer.
A similarly harsh name is Mr. M’Choakumchild, and it well describes how this teacher chokes the imagination and love of learning out of his students.
Mr. Bounderby is another name that suggests the nature of its owner. A bounder was a common word to describe a disreputable, dishonorable person in Victorian England, and Bounderby lives up to this moniker.
Mrs. Sparsit's sharp name, which includes the word "sparse," also tells us something about the sharp-eyed spy she will turn out to be. Likewise, Mr. Harthouse has the word "heart" in his name, and it sounds like "hothouse," as in a hothouse flower—something artificial. He fittingly tricks unhappy Louisa into an affair with him.
On the more positive side, Cecilia (Sissy) Jupe, has a somewhat poetical name, befitting a circus girl with strong emotions and an imagination.