Just weeks after investment bank Goldman Sachs advised clients to bet against the loonie, global currency traders appear to be doing just that.

Bets against the loonie surged by more than a third in one week, the Globe and Mail reports. According to numbers from the U.S. Commodities Futures Trading Commission, there were $5.4 billion in short positions against the Canadian dollar last week, up by $1.5 billion in a week.

That’s the highest number of bets against the loonie since last spring, when short positions against the currency hit an all-time high.

There are numerous reasons analysts expect the loonie to keep falling, chief among them weakness in resource prices. Canada’s dollar generally tracks commodity prices.

In its report, Goldman Sachs noted that Canada has had a trade deficit — which normally means a declining currency — for the past five years. But the country avoided a sinking loonie because of the strength of its financial system, which attracted a lot of foreign investor money.

That foreign investment has now hit the brakes, Goldman Sachs said, and that’s reflected in a declining Canadian dollar.

A weaker dollar could be bad news for cross-border shoppers and people traveling abroad during the holiday season. Some travel companies are already considering slapping a “currency surcharge” on the price of package vacations. Many of these companies’ costs are in U.S. dollars.

But what’s bad news for travelers could be good news for retailers, who can expect to see more shopping at home if prices in the U.S. are higher for Canadians.

The loonie has been on a downward trajectory for much of the year, hitting its high point for 2013 in January, at above $1.01 U.S., before declining to around the 94-cent U.S. mark in recent weeks.

Some economists have suggested Bank of Canada Governor Stephen Poloz may be intentionally trying to sink the loonie, in order to help Canada's flagging exports. Poloz officially denies this.

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  • Molsons Bank $5 bill

    This Molsons Bank bill is dated 1922. Yes, Molson was a bank. It was launched in 1850 by two sons of legendary brewer John Molson, and issued its own currency until it merged with the Bank of Montreal in 1925.

  • Molsons Bank 10-shilling bill

    This 10-shilling bill from Molsons was issued in 1853. Canada used a variation of the British currency system (pounds, shillings etc.) until 1853.

  • $1, $2 and $5 bills from Molsons Bank

    Issued in 1837.

  • Bank of Montreal $1 bill

    The Bank of Montreal issued its own currency until the Bank of Canada became the monopoly currency issuer in 1935. This is a one-dollar or five-shilling bill.

  • Bank of Nova Scotia five-pound bill

    1820-1830s.

  • Colonial Bank of Canada $1 bill

    1859.

  • Champlain and St. Lawrence Railroad

    These uncut bills from one of Canada's earliest railroads have a face value of half-dollar, 15 pence, and seven pence half-penny.

  • Mount Royal College Bank $50 bill

    Issued in 1881.

  • Union Bank $5 bill

    1867.

  • "Bank of True Love" - 50-token note

    This "bill" from the "Bank of True Love" is worth 50 tokens of affection. Of course, Canada never recognized tokens of affection as currency - this was a greeting card, which the McCord Museum dates as originating between 1880 and 1910.

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    The evolution of the Canadian one-dollar piece

  • Bank of Montreal Dollar - 1825

    Until the mid-19th century, Canada's future provinces used the "Canadian pound." Bit by bit, various jurisdictions began to switch to a metric system, and with it came the concept of the Canadian dollar. This Bank of Montreal-issued dollar bill is among the first bills called a dollar to have been printed.

  • Bank of Montreal Dollar - 1859

    Various banks printed their own currency until eventually the Bank of Montreal was charged with being the official issuer of the Canadian dollar, a practice that stayed in place until the Bank of Canada was created in the 1930s.

  • Bank of Toronto Dollar - 1859

    The Bank of Toronto (today known as TD Bank) was among many banks that issued Canadian dollars in the second half of the 19th century.

  • Ontario Bank Dollar - 1861

    Image courtesy of the Bank of Canada.

  • Province of Canada Dollar - 1866

    The province of Canada comprised Ontario and Quebec and existed from 1841 to 1867. It issued its own currency. Image courtesy of Bank of Canada.

  • Dominion of Canada Dollar - 1870

    With confederation in 1867, the first truly national Canadian dollar came into being. Image courtesy of the Bank of Canada.

  • Dominion of Canada Dollar - 1898

    Image courtesy of the Bank of Canada.

  • Dominion of Canada Dollar - 1911

    Image courtesy of the Bank of Canada.

  • Dominion of Canada Dollar - 1917

    Image courtesy of the Bank of Canada.

  • Dominion of Canada Dollar - 1923

    Image courtesy of the Bank of Canada.

  • Bank of Canada Dollar - 1935

    The Bank of Canada took over the issuance of currency from the Bank of Montreal when it was created in the 1930s. Image courtesy of the Bank of Canada.

  • Bank of Canada Dollar - 1937

    Image courtesy of the Bank of Canada.

  • Canada Dollar - 1954

    The 1954 dollar was the first to feature Queen Elizabeth II and the first to simply say "Canada" on it, rather than featuring the name of a bank, province or referring to the country as a "dominion."

  • Centennial Dollar - 1967

    Image courtesy of the Bank of Canada.

  • Canada Dollar - 1973

    This was the last paper dollar issued in Canada. It was in circulation until 1987, when the loonie replaced it. Image courtesy of the Bank of Canada.

  • The Loonie - 1987

    The loonie replaced the one-dollar bill in Canada in 1987. Image: CP

  • Canada 125 Loonie - 1992

    The Mint issued a special edition of the loonie in 1992 to commemorate the country's 125th birthday.

  • Vancouver Olympics Loonie - 2010

    An Inuit inukshuk graced the tail of this loonie issued in 2010 to coincide with the 2010 Winter Games in Vancouver.

  • The Loonie - Anniversary Special - 2012

    The Royal Canadian Mint issued a special-edition version of the loonie in 2012 to commemorate the coin's 25th anniversary. Image: Royal Canadian Mint.