NEW YORK, Dec 10 (Reuters) - Speculators" net long positioning on the U.S. dollar fell in the latest week, according to calculations by Reuters and U.S. Commodity Futures Trading Commission data released on Friday. The value of the net long dollar position slid to $19.46 billion for the week ended Dec. 7, from $23.99 billion the previous week. That number from the previous week was the largest net long since mid-June 2019. U.S. dollar net long positions dropped for the first time in two weeks. U.S. dollar positioning was derived from net contracts of International Monetary Market speculators in the Japanese yen, euro, British pound, Swiss franc, as well as Canadian and Australian dollars. In a wider measure of dollar positioning , which includes net contracts on the New Zealand dollar, Mexican peso, Brazilian real and Russian rouble, the greenback posted a net long position of $19.902 billion this week, from $24.435 billion in the prior week. Analysts said there were bouts of short covering that hit the U.S. currency against the euro and yen, especially after the dollar index hit its highest level since July 2020 two weeks ago. The dollar has been supported the last few weeks by a hawkish Federal Reserve Chair Jerome Powell who said, in remarks before Congress, that the risk of inflation has increased, as he pushed to accelerate the tapering of the central bank"s asset purchases. The dollar"s rally seemed to have run its course for now, analysts said, ahead of a Fed policy meeting next week in which the U.S. central bank will likely announce that it will wrap up bond purchases sooner than expected. "We think the bar for a hawkish surprise from the Fed next week is set high – money markets already discount roughly three 25 basis-point hikes next year," said Jonathan Petersen, markets economist at Capital Economics. "With that in mind we think that unless the FOMC delivers a major revision to its forward guidance, the dollar rally looks due for a pause," he added. That said, Petersen noted there is scope for the greenback to resume appreciation over the course of next year as he believes other major central banks are likely to raise rates more gradually than the Fed. In cryptocurrencies, bitcoin futures" net short positions dropped to 908 contracts this week, from net shorts of 1,691 in what has been a volatile week. Two weeks ago, bitcoin"s net short positioning sank to 160 contracts, the smallest since mid-January 2019. Bitcoin sentiment has been fragile all week after a flash crash last weekend wiped out 22% of its value. read more The world"s largest cryptocurrency was last up 1.7% at $48,383 but was down 2.2% for the week. Analysts said bitcoin"s failure to hold above $50,000 has prompted some selling. Japanese Yen (Contracts of 12,500,000 yen) $6.943 billion 07 Dec 2021 week Prior week Long 13,148 14,585 Short 76,229 93,451 Net -63,081 -78,866 EURO (Contracts of 125,000 euros) $1.168 billion 07 Dec 2021 week Prior week Long 194,869 191,048 Short 203,168 214,288 Net -8,299 -23,240 POUND STERLING (Contracts of 62,500 pounds sterling) $3.168 billion 07 Dec 2021 week Prior week Long 48,950 52,099 Short 87,227 90,998 Net -38,277 -38,899 SWISS FRANC (Contracts of 125,000 Swiss francs) $1.629 billion 07 Dec 2021 week Prior week Long 2,838 3,927 Short 14,891 18,109 Net -12,053 -14,182 CANADIAN DOLLAR (Contracts of 100,000 Canadian dollars) $0.74 billion 07 Dec 2021 week Prior week Long 41,095 41,242 Short 50,453 55,317 Net -9,358 -14,075 AUSTRALIAN DOLLAR (Contracts of 100,000 Aussie dollars) $5.822 billion 07 Dec 2021 week Prior week Long 33,380 33,217 Short 115,172 113,402 Net -81,792 -80,185 MEXICAN PESO (Contracts of 500,000 pesos) $1.525 billion 07 Dec 2021 week Prior week Long 70,791 85,840 Short 134,917 145,587 Net -64,126 -59,747 NEW ZEALAND DOLLAR (Contracts of 100,000 New Zealand dollars) $-0.727 billion 07 Dec 2021 week Prior week Long 31,881 30,465 Short 21,173 19,835 Net 10,708 10,630 Reporting by Gertrude Chavez-Dreyfuss in New York Editing by Sonya Hepinstall and Matthew Lewis