Accounts show that Hardy spent as much as $18.01 million on Taboo, while its income reached $14.54 million, meaning Hardy took a sizeable financial hit on making the show.
However, the Hollywood star still hopes to recoup more money through DVD and digital sales, while he can also sell the rights abroad.
The source told The Sun newspaper: "Tom will hope to eventually make the money back through DVD sales, downloads, streaming and syndication rights.
"As well as being aired in the UK and in the US, Taboo has already been sold around the world in the likes of Spain, Portugal and Russia."
Hardy came up with the idea for Taboo along with his dad Edward 'Chips' Hardy, and Sir Ridley Scott agreed to produce the project after the BBC purchased the rights.
Although the show has proven to be a financial flop thus far, plans are already in place to make a second series.
The drama has attracted relatively modest viewing figures, but is among the most-watched shows on the BBC iPlayer, the broadcaster's catch-up service.
The show airs Tuesdays at 8.30pm on SoHo.