By tracing each individual transfer rather than the total: origin documents such as sale agreements and tax filings, then bank statements for every account the money passed through, then formal documentation for any gift. Cash deposits without a documented origin are the hardest part of any such file.
Trace each transfer, not the total
Two questions are being answered, and they are different. Source asks how the money was lawfully earned, inherited, gifted or realised. Path asks how it travelled from there to the enterprise, account by account, with dates that reconcile. A file that proves an impressive source but skips two intermediate accounts is incomplete. Where funds came from a relative, a signed gift instrument, evidence of the giver’s own lawful source, and the transfer records are all needed, because a gift moves the source question upstream rather than removing it. Where cash was deposited, expect to reconstruct the underlying transactions or to use different funds.
Hypothetical example: an applicant from Roxton Pond assembles capital from two places: the sale of her share in a hardwood sawmill partnership, documented by a share transfer agreement and tax filings, and a gift from a grandparent that reached her as a series of cash deposits over several months. The first half is straightforward. The second requires the grandparent’s own records of where that money came from, a written gift declaration, and an honest account of why it moved as cash. If those cannot be produced, the cleaner answer is to fund the investment from the documented half and find the remainder elsewhere.