In every market rally, there should come a time when one takes a step back and gauges the broader picture. And when the craze continues for longer periods, the question 'Are the markets heating up?' would pop up in one's head. Some of the traditional indicators of the same include crazy valuations and unrealistic long term growth expectations. Then there are the subtle clues such as stocks being the main topic of discussion at dinner and cocktail parties. Then, there are clues that one could take from the foreign institutional investors (FIIs). As indicated in an article by the Mint recently, the authors discussed about how the concentration of holdings has changed over time. And this seems to be the trend as and when the market valuations start moving up. At the bottom of the growth cycle in 2002, the top ten stocks formed almost two-thirds of the FII holdings in the country. By the end of 2007, the top 10 stocks formed only about 35% of their holdings. In other words, FIIs increased their exposure to many more stocks. Coming to more recent times, the authors reports that the top ten holdings of FIIs in mid of 2013 formed about 50%; and that once growth rates pick up, this concentration could come down all the more.