Top 20 TSX Short Positions Dec. 15 [BlackBerry Ltd, Barrick Gold Corporation (USA), Yamana Gold Inc. (USA), Royal Bank of Canada, Kinross Gold Corporation (USA), Eldorado Gold Corp (USA), Enbridge Inc (USA), New Gold Inc. (USA), OSISKO MINING CORP] - Seeking Alpha

Top 20 TSX Short Positions Dec. 15 [BlackBerry Ltd, Barrick Gold Corporation (USA), Yamana Gold Inc. (USA), Royal Bank of Canada, Kinross Gold Corporation (USA), Eldorado Gold Corp (USA), Enbridge Inc (USA), New Gold Inc. (USA), OSISKO MINING CORP] - Seeking Alpha

This is an outstanding article about short positions involving Canadian stocks.  It is worthwhile paying attention to shorts especially if you own a stock that is heavily shorted.  As the author mentioned, the same short interest can be found at the Wall Street Journal concerning American stocks.

Twitter (TWTR) was one U.S. stock that was growing in short positions, and it fell more than $9 per share on Friday.  I own Twitter as a long term holding because I think mobile phones and advertising have a great future.  However, you should not put your rent or mortgage money on TWTR.  The volatility in the stock will present outstanding trading opportunities, though.

For example, Twitter was downgraded by a brokerage firm when it went over $70 per share.  The weak hands and traders immediately sold the stock to take profits.  Eventually, though, TWTR will get back to $70 per share and beyond because people know mobile stocks are worthwhile.  Then, another brokerage firm might downgrade Twitter again, and the whole cycle will be repeated.  My point here is that you can probably make a lot of trading money on TWTR if you buy at $63 or less and sell it at $70 or better.  The trend is your friend until it no longer works.  Make the money while you can.