The tilde symbol (~) is used in academic texts in place of about or approximately.
Generally, it is placed immediately before the number (eg. AUD ~2.4 million), which works for positive numbers, where the positive symbol is not shown. However, when dealing with a negative number, the negative symbol is shown (eg. -3.7).
If this were an approximate value, would the tilde be placed before or after the negative symbol (~-3.7) or -~3.7)?