I noticed that too around two weeks ago. Some history about GMTX I looked up is that they're based in Chicago and are over 110 years old. They also came up in this unrelated Craine's story about tank cars:
http://www.chicagobusiness.com/article/20131026/ISSUE01/310269977/oil-boom-is-creating-years-long-backlog-for-tank-cars"As demand increases, the good fortune trickles down to car lessors such as Chicago-based GATX Corp., whose prices have increased more than 20 percent in five years.
“We've seen dramatic increases in tank car rates over the last 18 months due to the unprecedented demand for the cars,” GATX President and CEO Brian Kenney told investors in a July conference call. The company's stock closed Oct. 25 at $51.21, up 22 percent from a year ago.
Chicago's historic status as a transportation hub makes it ground zero for the boom. Six of the nine major tank car players are based in the region: Union Tank Car and lessors GATX, GE Capital Railcar Services, CIT Group Inc., Flagship Rail Services LLC and First Union Rail Corp."