据3名知情人士称，美国可能结束为期4年的针对白银市场可能存在操纵行为的调查，因为美国监管机构未能发现足够多的证据，无法提起诉讼。
2008年9月，美国商品期货交易委员会（CFTC）宣布，正就白银市场存在不当行为的指控展开调查，此前，一些贵金属投资者提出了大量操纵指控。
2010年，CFTC的一名委员巴特·切尔顿（Bart Chilton）表示，他认为，市场上存在以欺诈手段不正当控制白银价格的做法。
但知情人士称，在听取两名外部顾问的建议后，CFTC的工作人员没有找到足够多的证据提起诉讼。其中一名顾问发现了某些交易日期的反常，CFTC认为，对于这一问题需要进行更多的分析。
CFTC的5名委员尚未正式确定调查结果，因此该机构也有可能会指示其工作人员展开更深入调查。
CFTC表示：调查尚未做出结论。CFTC拒绝进一步置评。
结束调查将激怒美国一些白银投资者，他们声称，一些大型投行——尤其是摩根大通（JPMorgan）——共谋推低白银价格。
一名了解此次调查的人士表示：这样的结果肯定会激起某些激进白银投机者的担忧。
在最近一篇博客中，时事通讯发布者、白银投资者的非官方支持者泰德·巴特勒（Ted Butler）指责CFTC玩忽职守，未能终止白银市场持续存在的显而易见的操纵行为。
CFTC去年表示，自调查开始以来，该机构对10万多份文件进行了分析，并采访了多名证人。
知情人士表示，证据包括来自摩根大通的记录。
A four-year investigation into the possible manipulation of the silver market is likely to be dropped after US regulators failed to find enough evidence to support a legal case, according to three people familiar with the situation.
The Commodity Futures Trading Commission announced in September 2008 that it was investigating “complaints of misconduct in the silver market”, following a barrage of allegations of manipulation from some precious metals investors.
In 2010, Bart Chilton, a CFTC commissioner, said that he believed there had been “fraudulent efforts” to “deviously control” the silver price.
But after taking advice from two external consultancies, the first of which found irregularities on certain trading dates that it believed deserved more analysis, CFTC staff do not have sufficient evidence to bring a case, according to the people familiar with the situation.
The agency’s five commissioners have not yet formally determined the outcome of the investigation, leaving open the possibility that staff could be instructed to dig deeper.
The CFTC said: “The investigation has not reached its conclusion”. It declined to comment further.
Ending the probe would infuriate some US silver investors, who claim that a group of large investment banks – in particular, JPMorgan – has conspired to drive the price of silver lower.
“I’m sure it will be met with some concern from a certain group of aggressive silver speculators,” said one person familiar with the investigation.
In a recent blog post, Ted Butler, a newsletter publisher and unofficial champion for the silver investors, accused the CFTC of being “negligent in failing to terminate the obvious manipulation ongoing in silver”.
The CFTC has analysed more than 100,000 documents and interviewed dozens of witnesses since it began its investigations, it said last year.
The people familiar with the situation said the evidence included records from JPMorgan.
