Mystery Nasdaq algorithm accounted for 10% of bandwidth last week

A single mystery algorithm that placed and cancelled orders on Nasdaq's stock exchange accounted for 4 percent of all quote traffic on the US stock market last week, according to market data firm Nanex.

The algorithm also accounted for a mammoth ten percent of the bandwidth that is allowed for trading on any given day, but the motive behind its presence is still uncertain.

It placed orders in 25-millisecond bursts, which included about 500 stocks, but never actually executed a single trade. The algorithm's activity ended at 10.30am ET on Friday.

"Just goes to show how just one person can have such an outsized impact on the market," Eric Hunsade, head of Nanex, told CNBC.He added: "Exchanges are just not monitoring it."

Although the exact motive behind the algorithm is still unclear, it that a trader could have been testing the water to see how he or she could use the additional bandwidth to create a latency advantage.

By using up additional bandwidth, the program could potentially slow down others trying to execute trades, allowing it to buy and sell on information that its competitors wouldn't receive until fractions of a second later.