Opening profit on NYSE? (6)

I believe the answer is:

window

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'opening' is the definition.
(window is a kind of opening)

I don't understand the remainder of the clue.

(Other definitions for window that I've seen before include "Transparent part of envelope" , "Skylight" , "Opening to admit light" , "Glass-filled opening" , "Shop display area" .)

I've seen this clue in The Telegraph.

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