How to measure retail sentiment in the markets?

Also since so few people are interested in stock markets (none of my friends are bothered), is it safe to believe that we are not in a bull market?

Yes, you could say interest about the stock markets and investing in general is quite low. But interest is slowly picking up again. I've attached screenshots of Google Trends analytics showing interest over time in various stock indices in the respective countries. As you can see, most interest is around 2007 - 2008, when there was a bull rush.



NIFTY - India



Dow Jones



NIKKEI 225



HSI



STI

As you can see, there is a peak in the interest in the 2007 - 08 range everywhere and despite an exponential increase of people with access to the internet, the hits for these indices are lower now, so one might say that we're NOT in a bull market.