The rapid expansion of the global cryptocurrency market raises the question of whether there are stable relationships between the prices of representative cryptocurrencies and economic indicators capturing expectations of future monetary policy. In this paper multivariate time-series analysis reveal a single but significant cointegrating relationship between cryptocurrencies and the term spread. This evidence reveals direct policy implications for the implementation of monetary policy allowing for the growing influence of digital assets. While the cointegrating linkage plays a critical role in modelling cryptocurrencies in sample, it contributes little to forecasting them out of sample, thus indicating potential efficiency in the digital currency market.