If financial investors were to write letters to Santa Claus this Christmas, they would probably be tempted to ask for the continuation of the unusual combination of factors that has dominated over the last year: ultra-low market volatility, booming financial-asset values, correlations that lower the cost of portfolio risk mitigation and promising new opportunities (such as bitcoin).

But before making their wish list, investors should consider the longer-term risks associated with the decoupling of financial markets from economic and policy fundamentals. Investors could be forgiven for hoping for more of the same.