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Well, this ought to be interesting - not for what might be revealed, but for what will likely remain in the shadows.

One of the weakest, least effective regulatory bodies around, the Financial Industry Regulatory Authority (FINRA), is now saying they want to shed some light on "dark pools."

FINRA is the self-regulatory body, backed and stacked by the broker-dealers and brokerages that channel your trades from your desktops and through brokers, whom FINRA is responsible for registering and regulating, to various exchanges for execution.

They're going to be looking into dark pools, which are off-exchange trading venues where stocks are traded "blindly." That's supposed to mean buyers and sellers don't know who's who.

But the truth is, even dark pool customers are blind to how these shadow operators really operate.

Here's the deal...

There are obvious problems with dark pools.

According to a recent Wall Street Journal article, "In 2011, the SEC fined Pipeline Trading Systems LLC, a now-defunct New York dark-pool operator, $1 million for allegedly failing to disclose that a secretive trading unit interacted with the vast majority of client orders. Pipeline didn't admit or deny wrongdoing. Last October, a dark pool operated by several large Wall Street banks, LeveL ATS, settled SEC allegations, without admitting or denying wrongdoing, that it improperly shared confidential client trading information with a unit of Citigroup Inc., one of its investors."

So the first question I have, and you might want to ask, is this:

How come the SEC, which oversees FINRA and is infinitely more powerful than FINRA (though that's a relative thing considering how spineless the SEC is), isn't itself peering deeper into dark pools?

I think we'll find the answer to that in a moment.

Anyway, FINRA just sent "examination letters" (polite letters asking polite questions, on account of the fact that the self-regulatory regulator is looking into some of their own here) to 15 dark pool operators.

Three of the biggest operators are Goldman Sachs, Credit Suisse Group AG, and Barclays Plc. Collectively, as calculated by market research firm Tabb Group, about 13% of daily trading volume happens in dark pools.

So FINRA figures it looks good if it asks what really goes on in the depths of dark pools.

Do dark pool customers know how operators may be operating on them, without them knowing? Are dark pool operators playing their customers by manipulating prices at public exchanges to influence trading orders and execution prices in their dark pools?

Are dark pool operators who act as market-makers - meaning they trade for themselves based on where the orders they are "seeing" are coming from to buy and sell and how big those orders are - using the "order flow" their big customers believe is "blind" to their inside advantage?

I'll save FINRA some time, and the lapdogs at the SEC who let this happen under their watchful eye (they only have one, the other is a marble).

The answer is, of course, "yes."

Dark pool operators are employing high-frequency trading computer technology to read incoming quotes and orders going to the public exchanges so they can do what HFT operators do, manipulate quotes and orders, including in their dark pools, where they have captive customers trading blocks. Customers who don't know that, most of the time, the trader on the other side isn't another institution, it's the house in whose basement without windows they expect to be treated fairly.

But it's okay.

FINRA will ask polite questions and turn over some of the answers they get to the SEC. And the SEC will tell them to bury the bad news and write a report that promises to ask non-offending offenders to incorporate more safeguards to make sure what's happening isn't ever fully disclosed.

Why? Because the SEC, who let all this happen, can't let the world know that the markets they are supposed to ensure are fair and orderly are actually a casino rigged by the house, for the house.

End of story.

This article originally appeared at Money Morning. Copyright 2014.