This round-table discussion focuses on two major aspects of the use of alternative currencies. The first is the role of negotiation. The complexity of valuation in exchanges in kind has been widely highlighted. However, it is important to emphasise the relative subjectivity of this operation which, despite the explicit reference to the market price, retains a cultural dimension. This observation means that we must not overlook the individual or category dimension of the transaction, which can tip the exchange in favour of one or other of the parties, resulting in a form of dependency. The second component is mistrust. Distrust appears to develop on the soil of the abuses observed. The fear or feeling of being duped. The vocabulary bears witness to this, but not without revealing a certain ambiguity in ancient societies with regard to bartering, which invites us to look beyond the negative value of the vocabulary and consider the bias that may be introduced by contractual sources that mainly bring together strangers.