A live look at fund managers crowding into the long bitcoin trade. Reuters/China Daily Count large fund managers among those unable to resist the allure of bitcoin's massive returns.

Owning the scorching-hot cryptocurrency — which has surged more than 350% this year — is seen as the most crowded trade to a pool of 214 fund managers overseeing $629 billion, according to a survey conducted by Bank of America Merrill Lynch.

To be specific, 26% of investors surveyed in September said they viewed being long bitcoin as the most crowded position. Coming in second place and being dethroned from the top spot was the long Nasdaq trade, with 22% of responders mentioning it, BAML's data showed.

Long bitcoin is the most crowded trade right now, according to a monthly BAML fund manager survey. Bank of America Merrill Lynch

But while bitcoin has seen unbelievable gains in recent months, its price has fallen from a record high reached on September 1 amid a Chinese crackdown on cryptocurrency exchanges. The reported ban comes after China decided to halt initial coin offerings, a hot new way for startups to raise funds by generating their own virtual currency.

Further, Nobel-winning author Robert Shiller, who predicted the two biggest speculative markets in recent history, recently doubled down on his view that bitcoin is a bubble in an interview with Quartz. BAML's survey shows large fund managers have yet to heed his warning — a choice made at their own potential peril.

Rounding out the top three most crowded trades in BAML's study is the short US dollar trade. The greenback has slid almost 10% in 2017, and hedge funds in particular have been keen to position for further weakness, according to recent Commodity Futures and Trading Commission data.

The prevalence of shorting the dollar marks a major shift for fund managers, for whom going long the currency was the number one investment as recently as April, capping off a five-month streak as the most packed trade.

The following chart shows the evolution of the BAML survey's most crowded investment, with bitcoin taking the reins in September: