There was a time when establishing what a person owned, beyond what they chose to disclose, was genuinely difficult work. It required specialist knowledge, considerable effort, and access that few people had. That is much less true than it once was.

Several changes have combined. Public records of property and corporate interests have become easier to search and, in many places, easier to reach. The requirements placed on financial institutions and professional firms have produced a great deal of structured information about who holds what. Investigation has professionalised, and the people who do it are more numerous and better equipped. Cross-referencing one record against another, once laborious, is now ordinary.

The result is that holdings are more traceable than their owners often assume. A property held through a company, a company held through another, an interest recorded in one jurisdiction and echoed in a filing in another: each link in such a chain is a record, and records can be followed. A structure designed to be discreet is only as discreet as the least private of its parts.

This tracing is not only done by adversaries. It is done routinely by parties with entirely legitimate reasons: institutions meeting their obligations, firms conducting due diligence, researchers, parties to a dispute. The point is not that any of them is a threat. It is that the capability is widely held and routinely used, and a capability that is widely held should be assumed to be applied.

For a person of significant means, the practical implication is straightforward. The visibility of what one holds should be assessed honestly, structure by structure and jurisdiction by jurisdiction, on the assumption that the tracing of wealth is now an ordinary activity rather than a rare one.

A holding believed to be private, and in fact traceable, is a gap. The only way to know whether such a gap exists is to look for it deliberately, with the same thoroughness another party would.