ANZ became the latest bank to downgrade its yuan forecasts on Thursday. It now sees the yuan ending the year at 6.55 against the dollar, 2.3 percent down from around 6.40 now.
Short positions on the yuan rose to the highest since April 2010, according to the survey of 20 fund managers, currency traders and analysts conducted from Tuesday to Thursday. In April 2010, Reuters started including the Chinese currency in a survey of market positioning in emerging Asian currencies.
Sentiment on the yuan had been relatively optimistic since early April this year. But the Aug. 11 devaluation after a run of poor economic data has prompted fears of a "currency war". The yuan has lost 2.9 percent so far this year.
Chinese stocks have been on a roller coaster ride, signalling little faith among investors in the government's month-long effort to stabilize the market.
Emerging Asian currencies lacked upward momentum on Thursday although minutes from the Federal Reserve's last policy review indicated U.S. policymakers were not in a hurry to raise interest rates.
The Malaysian ringgit's short positions hit the highest since January 2007 when Reuters began to include the ringgit in the survey. Last week, the currency fell to its 1998 pre-peg low due to capital outflows.
Confidence in Malaysia has been sapped by falling commodity prices and corruption allegations that have linked Prime Minister Najib Razak to indebted state fund 1Malaysia Development Berhad.
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Offshore investors in the country's bond markets have stayed put through months of economic and political uncertainty but a sudden spurt in currency volatility appears to be testing that allegiance.
Foreign exchange reserves have fallen below the $100 billion threshold, raising doubts over Malaysia's ability to defend Asia's worst-performing currency so far this year, although its central bank chief does not see cause for worry.
Thailand's baht suffered the largest short positions since February 2012, when Reuters started including the currency in the positioning survey.
The baht slid to its weakest in more than six years as a bomb blast at a popular Bangkok shrine killing more than 20 people is expected to hurt tourism. Foreign investors on Tuesday reported their largest stock selling in more than 1-1/2 years.
Asian fund drain
The Taiwan dollar hit a near six-year low and posted the highest short positions since June 2006 when Reuters started the positioning poll.
Foreign investors continued to dump the island's stocks on growing worries that a sluggish Chinese economy will hurt exports.
The South Korean won reported the largest bearish bets since October 2008 as the country's stocks and bonds saw their largest monthly outflows in four years.
Singapore's dollar scored the largest pessimistic bets since January 2009 as it fell to a five-year trough. The currency closely tracks the yuan as it is believed to be included in the undisclosed currency basket used by the Monetary Authority of Singapore to manage monetary policy.
The city-state's currency has come under further pressure on growing risks of policy easing due to China's devaluation and a sluggish local economy.
Bearish bets in the Indonesian rupiah rose to their largest since December 2013. The rupiah hit a 17-year low as slowing growth and falling commodity prices has sparked selling in local stocks and bonds.
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The central bank said it was going all out to defend the rupiah with a plan to tighten curbs on dollar purchases over the counter.
Short positions in the Philippine peso increased to their highest since August 2013 as the currency touched a five-year low on continuous foreign stock selling.
The Indian rupee's bearish bets also hit a two-year high.
The poll is focused on what analysts and fund managers believe are the current market positions in nine Asian emerging market currencies: the Chinese yuan, South Korean won, Singapore dollar, Indonesian rupiah, Taiwan dollar, Indian rupee, Philippine peso, Malaysian ringgit and the Thai baht.
The poll uses estimates of net long or short positions on a scale of minus 3 to plus 3. A score of plus 3 indicates the market is significantly long U.S. dollars.
The figures include positions held through non-deliverable forwards (NDFs).