The SEC is about to weigh in on the battle that is dividing Wall Street

A battle that's been raging on Wall Street for nine months is finally nearing its conclusion.

IEX filed with the SEC to become a stock exchange in September, triggering an ugly war of words between its backers and its enemies.

Opponents of IEX's plan say that approving the application could destabilize the stock market. They include the New York Stock Exchange, and Nasdaq, which - through its law firm - said that the SEC could be sued if it approves IEX's application.

The SEC is set to decide on the application by June 18.

Business Insider sat down with Brad Katsuyama, CEO and cofounder of IEX, last week to discuss high-frequency trading, his mission, and the controversy surrounding the firm.

One question I asked is what happens next if the application is approved:

Matt Turner: You'll have news by June 18. What will happen if you get good news?

Brad Katsuyama: If there is good news, the brokers will need some time to connect and configure their systems, and we will give them some time to do that, and a couple months after that it would be our official launch date.

Turner: And what if there is bad news?

Katsuyama: If it is unsuccessful, hopefully we'll get details as to why. One of the challenges of going through this process is understanding exactly why. It is one thing for someone to say "IEX is unfair," but tell me exactly how it is, tell me exactly what rule. There has been a lot of rhetoric. There hasn't been a lot of specificity. There are many ways that we could probably protect investors, but understanding what we can't do and can do would be helpful for us as we try and re-craft a solution that may fit inside the regulation.

Turner: You would go again?

Katsuyama: Absolutely. Time is our friend right now. We're well capitalized and we're profitable, and we have a good base of supporters. We'll definitely go again.

Later in the same interview, I asked Katsuyama whether he thought his life would get easier once the SEC has made a decision. Here's what he said:

Turner: If you get approval, won't your life get easier? Does the controversy not die down?

Katsuyama: I don't know the answer to that. The money hasn't been lost; the wealth transference hasn't occurred. It will still be a battle. On June 17, we might get permission to compete. It is still a competition. It is still going to be fierce. I don't really plan on letting our guard down.

Turner: And how are you feeling ahead of the big decision?

Katsuyama: I try not to think about it too much. It is just another data point. Everything that needs to be said has been said. We've done what we can do, and I do believe we've done enough.