Arkhouse Management and Brigade Capital Management have increased their bid for Macy's by nearly $1 billion to roughly $6.6 billion.

Why it matters: Macy's had rejected the group's initial proposal, stating that it didn't offer "compelling value."

Catch up quick: The investor group has offered to buy the shares they don't already own for $24 apiece, up from the $21-a-share offer it made in December.

• The group said today that Fortress Investment Group and One Investment Management U.S. will contribute 50% of the equity portion of this new offer.
• Questions had loomed over how the original offer would be financed.

My thought bubble: The new offer, which represents a 33% premium to Macy's shares at Friday's market close, will be difficult to ignore given consumer behavior shifts and general headwinds department stores face.

The latest: Macy's said last week it planned to close 150 stores over the next three years as part of a turnaround plan.

What they're saying: "While the restructuring plan Macy's unveiled last week failed to inspire investors, the fourth quarter earnings and year-end results have given us further confidence in the long-term prospects of the Company if redirected as a private company," the investor group said in a joint release.

The other side: Macy's said in a statement that the board "will carefully review and evaluate the latest proposal" and won't comment further until that's complete.

Flashback: Arkhouse recently nominated nine candidates to Macy's board in another effort to put more pressure on the retailer.