A stone's journey helped create its value
Rai were carved from limestone obtained on other islands, especially Palau, and transported across dangerous seas. Size mattered, but so did quality, origin, production difficulty and the history of earlier transfers.
Yap also used other forms of exchange. Rai were not small coins for every purchase; they could mark major social transfers. Calling them the island's only currency would be misleading.
Ownership moved while the stone stayed
Very large discs were impractical to carry. A transfer could therefore be recognised by the community while the stone remained where it was. One famous account even describes a valuable stone lost at sea whose ownership continued to be acknowledged.
The example separates the physical token from the economic claim. A bank payment likewise changes records rather than moving a marked pile of coins. Money can operate through trusted records even when it has a physical symbol.
Not an ancient blockchain
The shared-ledger analogy is helpful: in both cases the community must recognise which transfer is valid. Rai had no global network of pseudonymous nodes, digital signatures, proof of work or mechanically executed software rules.
Trust on Yap rested on local knowledge, relationships and tradition. Bitcoin aims to make verification possible among strangers. Both highlight recorded ownership, but they use different mechanisms and face different risks.