The US seems expensive relative to other major stock markets. As it is probable that cheaper markets will give better returns, this implies that investors should underweight US equities. This conclusion applies, however, only over the longer term. Timing matters and this involves other considerations.

Chart one illustrates that G5 stock markets are strongly correlated with the US and so, to a large extent, markets go up and down together. The chart also shows that this tendency has been strengthening over time. Read more