Innovation may be hard to define, but to borrow from former U.S. Supreme Court Justice Potter Stewart, you know it when you see it. The United States economy is full of innovation. It has to be. Manufacturing industries that dominated the economy decades ago -- textiles, televisions, even automobiles, to a large degree -- have moved overseas, where costs are lower. Yet the U.S. economy is at its largest point in history and still growing. If U.S. corporations weren't innovating, creating new products and services, and moving into new markets and applications, the domestic economy would be contracting, not expanding, and capital would not be flooding into the country. Particularly at this juncture of the market and economic cycles, we look to innovative companies to navigate the challenges. At Argus, an 85-year-old independent research firm that has innovated a time or two in its long history, we have focused on four types of innovative companies: Industry Disruptors; First to Market; New Product Specialists; and Product & Process Perfectors. The following innovative and BUY-rated companies recently were added to our Growth model portfolio, as well as our new Innovative Growth Separately Managed Account, and our Modern Innovators UIT. The full list of stocks also is in our Innovation theme model portfolio.