MUMBAI: Was it a fat finger error or an algorithmic trade? That was the question that brokers were asking themselves after the Nifty futures fell and then dramatically recovered in early trades on Tuesday. At around 9:15 am, the Nifty futures opened for trading at 8422, but fell to 8000 at around 9:55 am and then quickly recovered more than 100 points within a few minutes.Brokers said the trade that caused an unusual fall could have originated from an algorithmic order while some felt it could be another incident of a fat finger error – where a trader mistakenly punches in a wrong order. The recovery triggered a stop loss for many small traders, said a broker.“As an exchange, we can confirm that all trades that have happened during the day remained within the trade execution ceilings/limits – as applicable when respective trades were taking place… Moreover, as an exchange, we don't track any particular trade in the way as many may think, as we are not party to trades (as buyer and seller). We have not received any queries on this from any authorities,” a spokesperson for the National Stock Exchange said, while responding to an ET’s e-mail query, adding that it could well be that certain parties were spreading rumour about an unusual trade.Usually, traders keep a range of 1% to 1.5% for Nifty index and their positions are automatically squared off if the index falls below such a trigger. This is what happened when Nifty futures of January hit unusually low levels at around 9:55 a.m. on Tuesday, causing a loss to some of the market participants. The size of a single Nifty contract, comprising 25 Nifty units, is a little over Rs 2 lakh and traders take positions by putting in 20-30% margin to brokers.A crash in Nifty futures in early trades resulted in margin pressure on those who were trading with a stop loss. Nifty futures of January shed 15.40 lakh contracts in open interest on Tuesday. “It looks mostly like an erroneous fat finger to me,” a derivative analyst with a foreign broker told Reuters.On October 5, 2012, the Nifty index had crashed 920 points wherein a trader with Mumbai based brokerage Emkay Global was said to have punched the trade.Nifty January futures plunge 5%, leaves players guessing if it’s an outcome an algorithmic trade.