A Surya Grahan (Solar Eclipse) will take place on 20th May / 21st May 2012. This will be first Surya Grahan in this year 2012 which is taking place in Taurus sign and Krittika star. I had a quick look at the the planetary configuration during the time of Surya Grahan and unhappy to say that it doesn't look good.
This Surya Grahan gives some indication of economic crises. I am no expert in economics and my little knowledge tells that it can be due to bad situation in Euro zone escalated from Greece problems. Overall, economy seems in a concerning state and hence does Indian share market / sensex and nifty.
I have written detailed article on AstroCAMP.com on this topic that can be found at - Solar Eclipse, Greece Default & World Predictions