The index has lost 3% or 519 points overall this week. It swung by 1.3% in intra-day trading on Friday, moving both ways.
By 12.22, it had recovered 204 points to 19,773 and then traded within a 100-point range for the rest of the day as Larsen & Toubro and Tata Steel stocks, battered after results, bounced back.
The benchmark index has been fluctuating sharply all through the week starting from Monday when it touched a 31-month high intraday.
“The single biggest reason for sharp fluctuations is heavy reliance on foreign institutional investments. As a result, any global development will have its repercussions on the Indian equity markets,” said Apurva Shah, head of research of broking firm Prabhudhas Liladhar.
FIIs have bought $ 14 billion ( Rs. 78,000 crore) worth stocks so far in 2013 but their anxieties are reflected in the market mood.