James Moore: What goes up must come down on the US markets

Outlook Another record for the Dow, which broke the 16,000 barrier as the more broadly based S&P 500 index broke the 1,800 barrier – both for the first time. Happy days are here again, right? At least for those who play the market.

Have a care. It is true the US economy is growing, and so are the profits of its great corporations. But the economy, and the prices of shares in its top companies, have been driven by cheap money from the Federal Reserve and rock-bottom interest rates. Policymakers will eventually have to remove the drip feed – that is, if some factor (inflation?) doesn't remove it for them. Gravity will bite in the end; if you've made a big profit from the surge, it may be a good time to sell up and book it.