  The resource-consuming mining of blocks on a blockchain equipped with a proof
of work consensus protocol bears the risk of ruin, namely when the operational
costs for the mining exceed the received rewards. In this paper we investigate
to what extent it is of interest to join a mining pool that reduces the
variance of the return of a miner for a specified cost for participation. Using
methodology from ruin theory and risk sharing in insurance, we quantitatively
study the effects of pooling in this context and derive several explicit
formulas for quantities of interest. The results are illustrated in numerical
examples for parameters of practical relevance.
