Money trail

"Money trail", is a catch phrase used to describe any evidence that money, or their equivalents, were passed between two parties. Money trails are left behind when funds are passed through something called a money loop. Unlike money laundering, that tries to wash funds to make them appear clean, money loop funds tend to start clean. However, they become dirty because they were used for a questionable purpose. The term dark money refers to funds that may have been passed into a money loop and not reported to election committees and voters.