Methodology: A fund is included when a filing shows a non-taxable in-kind contribution of securities into the ETF at launch. Scope is the CODE SECTION, not the transferor: separately managed accounts, a family office, a limited partnership, a private fund or a mutual fund all qualify, and the vehicle is recorded rather than used to exclude. Excluded are transactions citing a different provision: an IRC 368 reorganization is a merger, and an IRC 584 common trust fund transfer is its own section. Seed AUM and cost basis come from the N-CSR/N-CSRS in-kind contribution disclosure. Note that 51 of the 114 funds cite a filing that names Section 351 outright; the rest carry the label on the economics, an in-kind contribution at commencement with carryover basis retained, and the citation_strength column in the published CSVs says which is which.
*Estimated cost basis applies the AUM-weighted cost-basis ratio of funds with a filed N-CSR to those without one. It is an estimate, not a disclosure.