Speculators placed the largest bet since at least 2007 that the euro will fall against the dollar, last week wagering a net $19 billion that the troubles plaguing the currency union will hurt the euro, government data showed Friday.

The market's euro position as of Tuesday was up 18% over the prior week, totalling a net 116,457 contracts, according to the Commodity Futures Trading Commission's weekly report on the commitments of traders.

"People think the euro should be lower," said Shaun Osborne of TD Securities in Toronto. His firm forecasts the euro/dollar will hit $1.22 by the middle of 2012, well below today's $1.30 level.

Investors were correspondingly more optimistic about the dollar's prospects, betting a net $15.9 billion on its appreciation against major currencies, up 11% from the week before, the data showed.

In the yen, traders held a net $5.7 billion in bets that the currency will decline. That was down 8% from the prior week, or 35,600 contracts.

Speculators were also less pessimistic about the Swiss franc, trimming their net position by 8% to bet $1.4 billion on a Swiss depreciation. That position represented 10.481 contracts.

The U.K. pound remained the market's largest negative bet of the week, with a net $3.8 billion wagered, but traders pared that position by 10%.

Traders continue to think the Canadian dollar will decline, with a net $1.3 billion in bets on that view, but they are 35% less certain about that view. The market viewed the Australian and New Zealand dollars as more likely to rise, adding to bets in their favor.

The CFTC's weekly report shows speculative investors' positions in major currencies held against the dollar. It viewed the markets as of Tuesday.