New Delhi, July 28 -- Indian stocks could see more volatility this week as the Nifty struggled to hold above the 25,200 level last week. This key resistance has triggered a battle between bulls and bears, amid heavy selling by foreign investors.

Bears concluded four straight weeks of negative closing last Friday- the Nifty fell by 3.12% from 27 June to 24,837 on 25 July- with heavy open interest accumulating at the 23,900 strike Nifty call option expiring this Thursday.

At closing on Friday, bears raised open positions- outstanding sell positions- of the 24,900 call by a whopping 962% to 86,159 contracts (one contract comprises 75 shares).

"The sale shows that bears are confident, at least for now, of the market remaining below 24,900 ...