ShiftPixy Inc. (NASDAQ: PIXY) is investigating possible “suspicious trading activity” in its stock, according to the company. ShiftPixy provides staffing and employment administrative services — payroll processing, workers’ comp administration and other services — primarily in the restaurant and hospitality segments. The Sunrise, Florida-based company announced the probe Thursday in a press release.

“I have been tracking naked short selling patterns since we first listed,” ShiftPixy CEO Scott Absher said in the statement. “We are now seeing algorithmic trading running wild as these trades appear to be run through a black box that is out-of-compliance with Regulation SHO and the Fair Market Making Requirement.”

“In a ‘naked’ short sale, the seller does not borrow or arrange to borrow the securities in time to make delivery to the buyer within the standard settlement period,” according to the US Securities and Exchange Commission. “As a result, the seller fails to deliver securities to the buyer when delivery is due (known as a ‘failure to deliver’ or ‘fail’).” Naked short selling is not necessarily a violation of federal securities laws.

The company said it engaged a registered broker-dealer to review trading data. The BD, which was not named, will also work with ShiftPixy to possibly file suspicious activity reports under the US Patriot Act’s FinCen 314(b). It’s a regulation that allows financial institutions to share information for the purpose of identifying and reporting possible money laundering or terrorist activity, according to the US Treasury.