Ready for Hillary, the super-PAC pushing for Hillary ClintonHillary Diane Rodham ClintonChris Murphy’s profile rises with gun tragedies DNC, RNC step up cyber protections Gun proposal picks up GOP support MORE to run for president, raised $4 million in 2013, a group spokesman tells The Hill.

The organization, which self-imposes a $25,000 maximum contribution limit, brought in more than $2.7 million in the final six months of the year from more than 33,000 individual donors.

"Thanks to the groundswell of enthusiasm for Hillary's potential run and the steadfast commitment of our supporters, we have exceeded our goals and are ahead of schedule in raising the funds necessary to build a grassroots army that can be activated the moment Hillary makes a decision," Ready for Hillary Executive Director Adam Parkhomenko says in a statement.

"This movement is unprecedented — not because of our staff but because of our supporters — and we will continue to build capacity across the country to put Hillary in the strongest position possible should she decide to run."

Ready for Hillary was started by supporters from her 2008 campaign and has since added some former Clinton advisers. It quickly became the go-to group for those looking to draft the former secretary of State to take another shot at the White House. Clinton increasingly appears to be moving toward a 2016 presidential run.

The group didn't disclose how much cash on hand it has. A spokesman says it has been investing in building out its supporter list. More than 600,000 people have signed its online pledge to back Clinton if she runs, and Ready for Hillary's Facebook page has more than 1.5 million followers. The group also supported Virginia Gov. Terry McAuliffe (D) and New York City Mayor Bill De Blasio (D) in their winning 2013 campaigns.