Things are getting out of hand in shares of another foreign telco, Rogers Communications ( RCI). The $24 billion Canadian firm has had investors betting against it en masse, pushing its short interest ratio up to a staggering 51.1. At that level, it would take more than two months of nonstop buying for shorts to exit their bets given current volume levels. It also makes RCI the most-shorted foreign stock on our list today. Rogers is Canada's largest wireless provider, a title that means a lot in an industry in which customer stickiness is partly forced by medium-term contracts and its TV, Internet and landline package deals. The firm boasts the nation's most advanced network. As the first carrier to introduce 4G LTE to Canada, Rogers is able to court customers looking for higher connectivity speeds, even if that advantage comes at a hefty cost. What many investors don't seem to realize is that in many cases short squeezes aren't fundamentally driven; they're typically structurally driven. That means that it won't necessarily take some huge positive earnings surprise in RCI to balloon its share price. Instead, the supply and demand forces of the market can create a positive feedback loop that forces short sellers to run for the exits. Bear that in mind now that RCI's short ratio is sky high.