Fans of Vince McMahon’s WWE are wondering if the 70-year-old pro wrestling impresario has run out of good storylines.

Ratings for “WWE Raw,” the company’s Monday night show on USA Network, have fallen nearly 50 percent from their 2015 high amid a slew of complaints from fans that the entertainment has become too predictable.

As one fan, Alex, posted on ratings blog “TV By The Numbers,” sagging ratings are the result of “too many matches with no storylines and a predictable and boring ending.”

Such opinions have been plastered over pro wrestling bulletin boards recently, which coincide with a months-long decline in the Monday night TV audience.

For example, the audience for the Nov. 23 show slipped below the 3 million threshold — to 2.96 million — from a high of 5.36 million in March, according to WrestlingNewsWorld.com data.

As recently as Aug. 31, the audience was still pushing 4 million — at 3.89 million. However, the last three months have seen a sharp fall-off.

The audience for “Smackdown,” WWE’s Thursday night show on SyFy, fell to 1.65 million viewers on Thanksgiving Day, down 44 percent from its high-water mark on Jan. 29.

Sources said the viewing pool was expected to be drained by WWE’s over-the-top offering, WWE Network, whose 1.3 million subscribers have 24/7 access to the company’s content.

Despite the viewer slippage and storyline complaints, parent NBCUniversal is standing by its brute offspring.

“WWE programming delivers one of the most massive live audiences in cable on a weekly basis and is consistently a top performer for our networks,” NBCU told The Post. WWE said it had nothing to add to that comment.

Shares of the Stamford, Conn., company have been on a tear in 2015, rising 41 percent.

They gained 2.1 percent on Wednesday, to $17.43.