Samsung:It’s hard to think of another huge company with a stock as cheap as South Korea’s Samsung Electronics. Its shares could rally 50%.

Samsung Electronics could be the world’s cheapest mega-cap stock. Just don’t expect it to stay that way.

The South Korean maker of cellphones, tablets, memory chips, and big-screen TVs trades for eight times estimated 2014 earnings, and just five times projected profit excluding its massive stash of net cash and investments, which totaled $60 billion at the end of the second quarter.

Then again, Samsung itself is a colossus,...