The nine-episode thriller, in which cash-strapped contestants play childhood games with deadly consequences in a bid to win 45.6 billion won ($A52 million), became an international hit when it launched last month.
In comparison to its estimated net worth, the show cost just $US21.4 million ($A28.8 million) to produce, Bloomberg said.
According to the report, about 132 million people had watched at least two minutes of the show in its first 23 days, easily breaking the record set by UK costume drama Bridgerton, which was streamed by 82 million accounts in its first 28 days.
Netflix had earlier announced the show had amassed 111 million fans, but Bloomberg said those figures were based on slightly older data.
California-based Netflix estimated 89 per cent of people who started the show watched more than one episode, the news agency said, and 66 per cent finished watching the series in the first 23 days.
Netflix declined to comment on the report.
The series is the first Korean drama to snatch the top spot on Netflix in the United States, and has even spurred interest among people in learning Korean.
In China, where Netflix is unavailable without a VPN, a Beijing bakery has introduced a Squid Game-themed confection-making challenge in its store.
The show has even drawn positive comments from Amazon founder Jeff Bezos, with the billionaire calling the work "impressive and inspiring".
Amazon's streaming service Prime Video competes with Netflix.