Documents reportedly filed and discovered by the website VCExperts.com indicate the company filed a certificate to authorize a $950 million Series G round of preferred stock on Dec. 17.
The report also put the company's valuation at $6.4 billion.
The new round of funding comes just weeks after reports that the group-buying website rejected a $6 billion acquisition offer from Google.
Groupon has not commented publicly on either report.
Rounds A through F totalled $171 million, according to the website CrunchBase.com.