  Bitcoins and Blockchain technologies are attracting the attention of
different scientific communities. In addition, their widespread industrial
applications and the continuous introduction of cryptocurrencies are also
stimulating the attention of the public opinion. The underlying structure of
these technologies constitutes one of their core concepts. In particular, they
are based on peer-to-peer networks. Accordingly, all nodes lie at the same
level, so that there is no place for privileged actors as, for instance,
banking institutions in classical financial networks. In this work, we perform
a preliminary investigation on two kinds of network, i.e. the Bitcoin network
and the Bitcoin Cash network. Notably, we analyze their global structure and we
try to evaluate if they are provided with a small-world behavior. Results
suggest that the principle known as 'fittest-gets-richer', combined with a
continuous increasing of connections, might constitute the mechanism leading
these networks to reach their current structure. Moreover, further observations
open the way to new investigations into this direction.
