A Tesla Model 3 vehicle is on display at the Tesla auto store on September 22, 2022 in Santa Monica, California. Tesla is recalling over 1 million vehicles in the U.S. because the windows can pinch a person's fingers while being rolled up.

Tesla is still the top-selling electric vehicle brand in the U.S., but its dominance is eroding as rivals offer a growing number of more affordable models, according to a report Tuesday by S&P Global Mobility.

The data firm found that Tesla's market share of new registered electric vehicles in the U.S. stood at 65% through the third quarter, down from 71% last year and 79% in 2020. S&P forecasts Tesla's EV market share will decline to less than 20% by 2025, with the number of EV models expected to grow from 48 today to 159 by then.

A drop in Tesla's U.S. market share was expected, but the rate of the decline could be concerning for investors in Elon Musk's autos and energy company. As Musk focuses attention on fixing his recently acquired social media company, Twitter, Tesla shares closed down by about a point to $180 on Tuesday. Tesla's stock has declined by almost half year to date.

S&P reported that Tesla is slowly losing its stranglehold on the U.S. EV market to fully electric models that are now available in price ranges below $50,000, where "Tesla does not yet truly compete." Tesla's entry-level Model 3 starts at about $48,200 with shipping fees, but the vehicles typically retail for higher prices with options.

"Tesla's position is changing as new, more affordable options arrive, offering equal or better technology and production build," S&P said in the report. "Given that consumer choice and consumer interest in EVs are growing, Tesla's ability to retain a dominant market share will be challenged going forward."