Reuters
All markets are prone to bubbles, where investors get overenthusiastic about a particular asset. The tricky bit is spotting them before they pop.
Analysts at UBS have found a way to crunch the numbers to do just that.
At the start of the year they said US health stocks looked expensive and shares in global energy firms were cheap - and they were right.
Here's UBS:
The energy sector no longer stands out as a crowded sell in the US and developed Europe, but remains a crowded sell for Asia ex-Japan. The over-bought pressure in the US and Asia ex-Japan Healthcare sector has also released to a certain extent, albeit for the US all three indicators are still relatively high compared with historical levels.
This time around the expensive shares are in the European tech industry, which are soaring after recommendations to buy from investment banks. Meanwhile, stocks in Asian banks look cheap, according to UBS:
New sectors that stand out European IT emerged as the crowded-bought sector, driven mainly by the Semiconductor names. In Asia ex-Japan, the Financials sector continues to deteriorate, reflecting ongoing concerns around Asia's credit cycle.
And here's the chart:
UBS
And here's the chart showing that recommendations to buy European tech stocks are at historical highs:
UBS