On Thursday, NYSE Euronext received approval from the U.S. Securities and Exchange Commission (SEC) to establish what is billed as a “first-of-its-kind” retail liquidity program that allows the sub-penny pricing of stocks for individual investors.

The program, approved for a one-year pilot, is expected to launch on Aug. 1. It gives retail investors a pricing advantage previously enjoyed only by the privately facilitated “dark pool” block trading used by institutions like hedge funds and pension funds.

The actual savings, however, amount to only a fraction of a penny, with a price break minimum of $0.001 per share. A 1,000-share trade might be discounted by only a dollar or two in most cases.

In October, the New York Stock Exchange LLC and NYSE Amex each filed a proposed rule change with the SEC for the program. In a statement, Joseph Mecane, executive vice president of NYSE Euronext, said the program would attract additional retail order flow and “ensure greater transparency, liquidity and competition throughout the U.S. cash equities marketplace."

In comment letters submitted to the SEC, the Securities Industry and Financial Markets Association (SIFMA) was among the organizations that took issue with the plan. It said the program “raises broad market structure concerns" as the exchange operates "what is effectively a ‘dark pool' for retail flow."

Among its issues were the exchanges' practice of charging member firms “a myriad of fees, including various types of access fees, market data fees and regulatory fees.”

“This new proposal would set up yet another reason to increase the regulatory charge, due to new retail participant flow identification and tracking,” it wrote.