Nifty and the movement of stock's price

Dear Friends,

This is to clear a doubt about the Nifty movement and price change, better say stock movement. yesterday i bought Manappuram Finance, L&T finace and Equitas, my entry was at a time when the price of these stocks were a little down and gradually the stocks picked up went up 1 to 2 %. Immediately the Nifty went down some thirty points eventually the price of my stocks also went down. After half an hour the Nifty regained the previous level, along with Nifty L&T finance and Manappuram finance also went up, but the price of Equitas couldn't move up to the previous level, of course it went up a little. One of my friends told me that it is due to the shorting at that time.
I request experienced friends to clear my doubt

Regards

Rajendran S