The third broad requirement of the market overt rule is that the sale must
be conducted in a certain manner and at a certain time. As we saw, this
requirement, in its odd way, provides some justification for depriving the
owner of his title. The judgment does not say if there is any such requirement
under the expanded rule. The sales were said to be ‘open’ not in the sense
of visibility but by reason mainly of the lack of reason for suspicion on the
buyer’s part. It is doubtful if this observation meets more than the next
requirement.
The fourth requirement of the market overt rule is that the buyer must be
a bona fide purchaser without notice of the defect or lack of title on the
part of the seller. This is also required under the expanded rule. In Caterpillar,
it was held that the defendants were bona fide purchasers. The bona
fide requirement appears to assume a central role in the expanded rule.
However, this requirement is the common denominator of almost all the
other recognised exceptions to the nemo dat rule; it has never and cannot
be sufficient in itself to defeat that rule. Hence what distinguishes theexpanded rule from the other exceptions and forms the core of the expanded
rule is the idea of a ‘regular and open market’. Considering the
significance of its role, the judgment, with respect, ought to have given a
clearer explanation of that concept. If it is given a wide meaning, the
expanded rule may come near to swallowing up all the other nemo dat
exceptions.