With U.S. stock futures trading slightly lower this morning on Friday, some of the stocks that may grab investor focus today are as follows:Greenbrier Companies Inc (NYSE:GBX) posted upbeat earnings for the first quarter, after the closing bell on Thursday. The company posted earnings of $1.14 per share, beating market estimates of 87 cents per share. The company's quarterly sales came in at$706.100 million versus expectations of $626.297 million, according to data from Benzinga Pro. Greenbrier shares slip ...