The power of "Squid Game"...Netflix has more than 300 million subscribers worldwide.

Shares surged in after-hours trading after the stock market closed as U.S. video streaming company Netflix recorded an "earnings surprise" in the fourth quarter of last year.

Netflix's revenue in the fourth quarter of last year was $10.247 billion (about 14.72 trillion won), up 16% from the same period last year.

In particular, the number of global paid subscribers increased by 18.91 million in the fourth quarter to 316.3 million.

Netflix said the number of paid subscribers excludes "extra member accounts" that register in one household, which are actually "pleasing to an estimated 700 million or more global viewers."

This increase in paid subscribers exceeds market research firm StreetAccount's expectations (29.9 million).

Netflix also raised its annual sales forecast to $43.5 billion to $44.5 billion (about 62.5 trillion to 63.9 trillion won) this year.

Driven by these strong results, Netflix shares jumped over 14% in after-hours trading after the stock market closed.

Netflix cited the Korean drama "Squid Game" Season 2 and Mike Tyson's boxing match and the NFL game performed by pop star Beyonce as the contents that contributed to the fourth quarter of last year's performance.

In particular, regarding "Squid Game" Season 2, he said, "It will be one of the most watched original series seasons," adding that the number of views in the fourth quarter was 165.7 million.

It also said that "Squid Game: Unleashed," released in the fourth quarter, topped Apple's app stores in 107 countries and is expected to be the most downloaded game of its own.

Netflix said it is "looking optimistic for the new year," citing "Squid Game" (Season 3), U.S. dramas "Wend's Day" (Season 2) and "Stranger Things" (Season 5) as the most anticipated films to be released this year.