The following charts from the FT starkly illustrate again how Tech dominates the global stock-markets, and what an extraordinary era of value creation has occurred in the last 8 years. Sceptics will fairly question whether this is a sign that prices are overheated. 

However, as the bottom chart shows, comparing valuation multiples of Tech from the end-90's bubble to now, the difference is clear - Tech stocks are now making vast amounts of profit.