A former Royal Bank of Canada employee who helped turn the spotlight on the practices of high frequency traders says parts of the market are rigged.

Brad Katsuyama, a native of Ontario, came to this conclusion while working at the RBC trading desk in New York City. While working on the desk, he realized a discrepancy between an order of stocks he wanted to buy and what he was actually able to buy.

He described the problem to BNN during an interview Tuesday. "If I saw 10,000 shares offered at $20, why was I not able to actually buy 10,000 shares at $20?" he said.

Katsuyama realized that when he placed an order of 10,000 shares, several different exchanges would fill it, working together to complete the order. And because there are multiple exchanges filling the orders, the exchanges are receiving the share orders at slightly different times – a phenomenon that he says is being exploited by high frequency traders, armed with high-powered computers.

These traders, who Katsuyama called “scalpers,” will notice that a large number of shares are being bought and will race ahead to the subsequent exchanges to buy up the remaining shares, which they can then sell for a slightly higher price.

The practice is essentially a form of electronic legal “front running,” with all the trades happening in milliseconds, only being picked up by supercomputers.

And while the boost in stock price typically amounts to fractions of a penny, for large investors this can add up, he said.

"High frequency traders could actually pick up a signal at one exchange, typically the one that was closest to us, and race us to subsequent exchanges. And that's how we were missing volume," he said.

He noted that while attempts to "game" the market are not in any way new, new technology has made it easier for scalpers to take advantage of the system using faster computers.

"People have always looked to game the markets, and right now what we see is no different," he said.

"People are using computers and technology in relationships with particular exchanges and dark pools (private exchanges that aren’t open to the public) to game the market. They're scalping."

Katsuyama and his discovery are profiled in Michael Lewis' newest book "Flash Boys: A Wall Street Revolt," which hit store shelves at the end of March.

The book is a critique of high frequency trading practices, and focuses on several different people who helped bring the issue to light. Since its release, Lewis and Katsuyama have made multiple media appearances to talk about high frequency trading.

Several U.S. agencies, including the FBI and the Justice Department, have recently disclosed that they have launched investigations into high frequency trading practices.

Yet despite his newfound fame, Katsuyama said his goal is to increase transparency and education, not to slam the industry.

"I think what it's about is a lack of transparency, it's about trust," he said, adding that he wants members of the financial services industry to band together and start to “repair the relationship” between Wall Street and Main Street.

In 2013 he opened up IEX, a new exchange that utilizes THOR, an electronic trading platform that uses delays so that orders of shares arrive at the different exchanges at the same time, thereby cutting out the possibility of scalping.