Bull: Lloyd O’Carroll, Davenport & Co.

Wall Street views Alcoa (AA), the largest U.S. aluminum producer, as a commodity stock. But about half its earning power comes from its midstream and downstream businesses. That includes rolled products, which go into beverage cans and automobiles, which are growth areas. Then there are engineered products, which are driven by the aerospace industry, where there’s a big backlog of orders. We expect the mid- and downstream businesses to grow 10%-plus over several years. The big question for the upstream [mining and smelting] business is, When might aluminum prices go up? They’re down 35% over two years, and the big rebound might be two or three years away. This isn’t a stock for a day trader. It’s for an investor who can see the underlying value.

Bear: Jorge Beristain, Deutsche bank

There are two big issues: First, aluminum prices face further headwinds. Regulators and consumers are pressuring the London Metal Exchange to change rules. That could unload more metals stored at its warehouses into the market. Alcoa’s engineered and flat-rolled products have done well, but its primary aluminum business remains a drag. They need to accelerate shutdowns of their cash-flow-negative smelters or look for creative ways to reduce them. Also, Alcoa has a very large debt load, and we think it’s going to go up again. Its debt is still rated investment grade by Standard & Poor’s and Fitch. But a one-notch downgrade could put Alcoa into high-yield status, leading to higher interest costs on its $8.3 billion debt.

This story is from the November 18, 2013 issue of Fortune.