Meh. Out of sheer curiosity, I checked ARTS in my Sharebuilder account where I maintain my self-employment 401(k). ARTS is not available through ShareBuilder. Due to a lack of market transparency, this company is designated as a "Grey Market" stock by OTC Markets (the primary quotation service for over-the-counter trading). There are no market makers in this security. It is not listed, traded or quoted on any U.S. stock exchange or the OTC Markets. Because of this, investor's bids and offers are not collected in a central spot so it’s nearly impossible to tell what the stock is really worth, and Best Execution of orders is difficult. I'm curious how much extra it costs to trade through some of these discount brokerages.