Baird analyst Andrew Wittmann suspects today's weakness in shares of Healthcare Services Group is related to the company not yet filing its annual report. The company noted on its February 6 conference call that it expects its 2018 filing the week of February 25, Wittmann tells investors in a research note. The lack of a filing this morning "has investors skittish about the unknown," says the analyst. However, Wittmann is not speculating on the hold up and adds that calls to the company were not immediately returned. He has a Neutral rating on Healthcare Services with a $39 price target. The stock in midday trading is down 3% to $36.46.