Christian Bale has a unique look in David O. Russell’s 9th film, Amsterdam (2022), and his hair in particular has an interesting story behind it. Amsterdam stars Bale, Margot Robbie, and John David Washington as three longtime friends embroiled in the historical Business Plot, a United States political conspiracy that occurred in 1933. Bale plays Burt Berendsen, a doctor and veteran of WWI which left him with a glass eye, a large scar across his face, and a back brace. Despite his injuries and constant pain, Burt has devoted himself to helping other injured veterans from the war, and he does so with gusto and vigor.

https://screenrant.com/amsterdam-christian-bale-long-hair-explained/