Magnussen, who will star in the Disney film adaptation of Into the Woods and was Tony-nominated for his performance in Vanya and Sonia and Masha and Spike, will play Greg Castman, the middle child of mogul James Castman (Brendan Gleeson).
The David Milch drama has also cast Rosemary Harris in the recurring role of Ellen Knox, the mother of James Castman's wife Ruth (Laila Robins); Mamie Gummer in the recurring role of Tricia Castman, who is married to John Castman (Patrick Kennedy), James and Ruth's son; Ray Liotta in the recurring role of George Archer, a wealthy Wall Street tycoon; Ruth Negga as series regular Erin Foley, a senior news editor; Morgan Spector as series regular Sidney; John Carroll Lynch in the recurring role of Robert Harris; and Tracee Chimo in the recurring role of private eye Jane Mulvaney, who works closely with reporter Gordon McCarren (Nathan Lane).
Milch is writing and executive-producing "The Money" with executive producers Art Linson and John Linson.
Justin Chadwick is directing the pilot and also serves as a co-executive producer. Frank Rich is also an executive producer with Eric Roth and Sarah Caplan.