I can put the amount in perspective: $3 trillion, or $3,000 billion, is more than Canada's GDP. These transaction or cash flows—some transactions occur more than once a year in various inflows and outflows of funds—are completely disproportionate to the economic activity of the country in question.
We looked at countries such as Tonga, small islands in the Pacific with a tiny GDP. However, the value of transaction flows between Canada and Tonga is several times higher than Tonga's GDP. No economic reason or transaction in property or services can justify flows of this magnitude from Canada to Tonga or from Tonga to Canada. It's completely disproportionate, given Tonga's GDP and the transactions in tangible property or services that occur there.
Clearly, this is purely for financial or tax reasons. There may be legitimate financial reasons, such as better interest rates or a more secure banking system, but I highly doubt this. I think that, aside from these legitimate reasons, few reasons justify transferring so much money to such a small country, other than tax reasons.