What does this "Change" mean in Charles Dickens’ ‘A Christmas Carol’?

The meaning of the sentence relies on the word 'Change, which is a shortened form of Exchange - the stock exchange. The sentence means that Scrooge had a good reputation on the stock exchange and that his signature carried weight. There is a clue to working out the meaning, since Change begins with a capital letter, indicating that it is a proper noun and not a verb or abstract noun in this context.

This is a note by Michael Slater:

'Change: The Royal Exchange in the City of London, which functioned as a trading centre from 1570 to 1939.

Michael Slater. Notes, p. 275. In. Charles Dickens. A Christmas Carol and Other Christmas Writings. London: Penguin Books, 2003.