How to read the band →
Solid line = floor (spellings that unambiguously belong to the group). Shaded band up to the dashed edge = ceiling (the most it could reach if every ambiguous spelling counted here).
Cassius
Cassius has stayed fairly steady in American naming for generations. All-time it's been given to 9,766 U.S. babies, the 1,044th most common name by sound today, peaking at 612 in 2021, with 504 in 2025.
Cassius has no common alternate spellings by sound.
Rising