Douglas Harper's Etymology Dictionary
"financial losses," 1929, from the red ink traditionally used to indicate debits in accounts.
Wiktionary
n. (context idiomatic business management accounting English) A euphemism for financial loss.
WordNet
Usage examples of "red ink".
The message was unequivocal, signed in red ink with a scrawled, testy signature that had creased and nearly torn the paper Marshal of Internal Security, Josef J.
On his left sat the Indian clerk, important, stern, precise, with small neat hands that wrote small neat figures in black ink and red ink in the tall ledger.
He looked at his hands, which were stained from the familiar red ink of his correcting pen (his so-called teacher’.
The words had appeared on the parchment in what appeared to be shining red ink.
He drew a snowy kerchief from inside his pocket and ruined it by wiping the red ink from his finger.
With the full power of the engines behind it, the Red Ink was transformed from a surface boat into a submersible.
Austin knew that battering Ali's boat off course would send the Red Ink off like a cue ball in a game of billiards.
The morning dawned dull and gloomy, and Villefort saw the dim gray light shine upon the lines he had traced in red ink.
He handed it to the boy, who noticed that on the inside was an address, written in red ink.
Arty-fatty red ink shooting out of a dozen people fucking and sucking.
He'd seen maps like this before, but on this one there were other places marked in red ink.