High-Frequency Trading

'I'm worried' about high-speed trading: Former Pimco exec

We need a level playing field: Kashkari

California gubernatorial candidate Neel Kashkari, a former managing director at Pimco, says high-frequency trading needs regulation, and another "flash crash" may be inevitable without it.

"Of course I think it should be regulated," Kashkari said Monday on "Squawk Box." "The idea that trading on nanoseconds or microseconds is benefiting the American consumer, the American economy? I don't buy it."

Kashkari was referring to the "flash crash" of May 2010 when the Dow lost 1,000 points and regained them in 20 minutes, a move largely attributed to traders using powerful algorithmic software and high-speed cables. Kashkari, a Republican who headed global equities at Pimco, told CNBC he doesn't think such practices can destabilize the markets, but that they don't add any value to the financial system.

Read More3 Years Later: Learning to Live With Flash Crashes

His comments come as financial journalist Michael Lewis caused a stir in the trading community Sunday night. During an interview on CBS' "60 Minutes," Lewis called the stock market "rigged" by a combination of investment firms, exchanges and high-speed traders. Lewis, the author of "The Big Short" and "Moneyball," was promoting his new book, "Flash Boys: A Wall Street Revolt," on the rise of high-frequency trading.

"I'm am worried," Kashkari said. "The complexity of all of these high-frequency traders, it's very hard to understand how all these things are going to interact. I can't imagine that's our last flash crash."

Read MoreMichael Lewis and why the stock market is 'rigged'

During an earlier interview on "Squawk Box," Themis Trading co-founder Joe Saluzzi said high-frequency trading is a symptom of a stock market that has made simple tasks increasingly more difficult. But that also makes solutions deceptively easy, he added,

While an outright ban on high-frequency trading doesn't seem necessary, Saluzzi says he believes two quick fixes could help shore up the inequalities caused by firms equipped with high-speed cables and powerful trading software.

"It's an overly complex system to do a very simple task," Saluzzi said. "You want to buy. I want to sell. Let's match up."

Read More Cramer stops short of calling market 'rigged'

High speed reality check

First, Saluzzi said exchanges should eliminate the "maker-taker" system, in which they pay traders who add liquidity into the markets and charge those who take liquidity out.

Secondly, exchanges should take a close look at its data fee structure. Saluzzi says data fees are a big factor behind the timing differences that created an arms race among high-frequency traders.

"There's always going to be someone smarter and quicker," Saluzzi said. "However you don't need a system ... that encourages a wire to be built."

Read MoreSEC official: Here's what makes markets 'unfair'

In 2012, Saluzzi co-authored a critical book on high-frequency trading called, "Broken Markets: How High Frequency Trading and Predatory Practices on Wall Street are Destroying Investor Confidence and Your Portfolio."

Saluzzi said he is also involved in an alternative trading system, IEX, which plays a big role in Lewis' book. Lewis alleges that a trader formed IEX to battle abuses from high-frequency trading.