Spot,

A similar sight was seen with Air Canada stock.

http://www.theglobeandmail.com/report-on-business/short-selling-scramble-sends-air-canada-stock-on-wild-ride/article1016865/

Through the Toronto Stock Exchange, the Canadian Depository for Securities is forcing these short sellers to provide the shares they've sold -- and cover their shorts -- through a "buy-in."

Typically, the investors would be forced to pay a 10-per-cent premium for the buy-in, but the TSX has increased the premium to 20 per cent to make sure it can access enough shares.

"Buy-ins have been a part of the market for a long, long time. Normally, they're executed at a modest premium to the current market, but when you get into a position like this . . . obviously to attract something you're going to have to give a little bit of a premium," Mr. Ketchen said.

Every time one of these buy-in trades is executed, Air Canada's shares instantaneously trade at 20 per cent above market price.

During the past week, this has created situations where shares have jumped back and forth between prices of about $2 and $2.40.

Because these buy-in trades are settled on a cash basis, they don't show up on trading records and aren't listed as the day's high trade. But they do show up in real-time trading data.

Brian Acker, president of Toronto money manager Acker Finley Inc., said short selling -- always a risky strategy -- becomes even more risky when investors haven't borrowed shares first.

The only way these investors will win is if the stock falls more than 20 per cent by the time they are forced to buy in to settle their trades three days later.

Observers suggest that many of the investors who sell short without borrowing are retail investors who may not understand the consequences