The video-streaming giant is reportedly taking a firmer stance against people sharing account passwords, testing a feature that prompts non-paying viewers to buy a subscription. A key question for Wall Street is how many will become paying users. While several analysts are confident that most won’t want to give up access to shows like “Bridgerton” or “The Queen’s Gambit,” the decision brings uncertainty at a time when rival services are adding millions of subscribers.

Netflix has underperformed as investors consider its post-pandemic prospects. The stock is up about 3% over the past six months, compared with a 13% rally in the Nasdaq 100 Index. Shares fell 1% on Monday.

For Benchmark Co.’s Matthew Harrigan, the underperformance will probably continue “as global consumers are disgorged from their couches” amid the Covid-19 vaccine rollout. The password crackdown could dampen Netflix’s pricing power, he noted.

Last week, Needham called user churn — the number of customers who drop their subscriptions — the top risk for Netflix in 2021.

Meanwhile, BMO Capital Markets is more optimistic, saying the strategy could “help drive some incremental gross subscriber additions.” Bloomberg Intelligence recently wrote that a crackdown “could increase revenue 10%,” although the move “risks alienating users, which could prompt elevated churn.”

Forecasts vary on what percentage of subscribers share their accounts with people outside their households. Bloomberg Intelligence said between 20% and 30% of Netflix’s 74 million domestic users potentially shared that information, while market-research firm Magid estimated that a third of subscribers did, citing a survey it conducted last year.

Netflix didn’t immediately return a request for a comment, but in a statement to the New York Times, it said the viewer prompt was “designed to help ensure that people using Netflix accounts are authorized to do so.”