Do I understand it correctly that Call(T,K_2) is written onto the same S? How does that help? Nor IV nor Vega is constant across strikes under BS. On another note, if we purchase a vol option instrument, then the entire equation makes sense. however, i'd correct the notation to C^1(T,K^1) to highlight the difference between C and C^1.
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Do I understand it correctly that Call(T,K_2) is written onto the same S? How does that help? Nor IV nor Vega is constant across strikes under BS.
On another note, if we purchase a vol option instrument, then the entire equation makes sense. however, i'd correct the notation to C^1(T,K^1) to highlight the difference between C and C^1.