U.S. podcaster Joe Rogan apologized and pledged more balance on his show amid a backlash against COVID-19 misinformation on the streaming service that wiped more than $2 billion off its market value last week.

On Monday, investors appeared to shrug off the controversy that hurt shares last week, as Spotify's stock price jumped 10% after brokerage Citigroup raised the stock rating to "buy" from "neutral" saying the Swedish company would be able to improve its advertising business.

Platforms' Influential Power

Spotify said it would add a content advisory to any episode with discussion of COVID to try to quell the controversy, a first step into the field of content moderation that other tech platforms have found challenging and costly.

Rogan's show, The Joe Rogan Experience, has been the most listened-to podcast on Spotify and is central to its plan to expand beyond music and take on rivals such as Apple and Amazon.com for a share of the podcasting market.

In a 10-minute Instagram video on Sunday evening, Rogan apologized to Spotify for the backlash but defended inviting contentious guests.

"If I pissed you off, I'm sorry," Rogan said. "I will do my best to try to balance out these more controversial viewpoints with other people's perspectives so we can maybe find a better point of view."

Rogan is a prominent vaccine skeptic and his views on vaccines and government mandates to control the spread of the virus alienated prominent figures from singer-songwriter Neil Young to guitarist Nils Lofgren to best-selling U.S. professor and author Brene Brown.

Singer-songwriter Joni Mitchell also asked for her music to be taken off Spotify, citing a letter from hundreds of medical professionals urging the platform to prevent Rogan spreading falsehoods on the pandemic.

Spotify, which reports its quarterly earnings on Wednesday, has spent billions to build its podcast business and currently has over 3 million titles on its platform. Although it has an exclusive license to distribute the podcast, Rogan himself owns the show.

According to the company, it reviewed the episodes and decided that they did not meet its threshold for removal.

Spotify CEO: We Cannot Be Censors

Spotify CEO Daniel Ek said late on Sunday that he might disagree with the views of some individuals on the platform but that it was "important to me that we don't take on the position of being content censor."

Its new policies include adding an advisory to any pandemic-related podcast that will direct listeners to a COVID-19 hub containing information from medical and health experts, as well as links to authoritative sources.

But the task of content moderation that it has now been dragged into is very different from removing songs with copyright violations, a job that Spotify is familiar with.

Social media giants Facebook, Alphabet's YouTube and Twitter have struggled with balancing the rights to free expression with moderating harmful content on their platform amid intense regulatory scrutiny. Technology companies have invested in human content moderators as well as artificial intelligence technology over the past few years.