I am old enough to have worked in an office where reports, letters and memos were handwritten and sent to a typing pool to be typed. Typists were trained to leave two spaces after a full stop (period). This was because typewriters use monospaced fonts — they have to because the reel has to move the same distance after each letter is typed. Two spaces after the full stop helped with the readability of the document. There were spaces between the letters within a word and it helped the reader to identify sentence endings by exaggerating the space after the full stop.
Most fonts on your computer, phone or table are not monospaced. They are proportional. It would be rare, I think, for a finance professional to produce a document in a monospaced font. I guess it would only happen if you wanted to make the document look like it was type-written.
Look at a word like “maximum”. In a proportional font (like Source Sans used on this site) the Ms are much wider than the other letters, and the I is very narrow. There are no gaps between the letters within a word. These fonts do not need, therefore, to have two spaces after a full stop.
Don’t believe me? If you type two spaces on a smartphone it replaces them with a full stop and ONE space.