unusual transaction

基本解释

Unusual transactions are the transactions which happen rarely because of the abnormal amount or nature.
非常规交易是指由于金额或性质异常而不经常发生的交易。
blog.sina.com.cn
Mr Woodford says his sacking may have more to do with some very large and unusual transactions that he challenged Mr Kikukawa and other executives to explain.
伍德福德称开除他的原因可能更多与他要求菊川冈以及行政部门对一些异乎寻常的大额交易做出解释有关。
When he spotted unusual bank transactions, Mr. Bernanke reported them to the bank. The Bernankes didn't lose any money as a result of the theft.
贝南克发现异常的银行交易后便报告了美国银行。伯南克一家并未因失窃遭受财产损失。
smilelyspring.spaces.live.com

This is but the latest in a serious of unusual transactions.
ECONOMIST: Emissions
Ramzam says that identity thieves frequently test credit card information by moving small sums of money, and banks have responded by scanning transactions records looking for unusual recipients of what look like test transactions.
FORBES: Magazine Article
Of course, there are limits in amounts and frequency of such transfers, and unusual behavior in mobile is monitored for fraud the same way that it is in credit and ATM card transactions.
FORBES: By Capturing Mobile Data, IBM's Clients Serve Their Customers Better