Tesla shares fell as much as 5.5% Tuesday, adding to their 6.5% drop on Monday, after Reuters reported that Apple is moving forward with autonomous technology and aims to produce a passenger vehicle by 2024 that could include its own battery design. Tesla’s two-day slump also follows its admission into the benchmark S&P 500 Index before the open on Monday.

“Apple’s potential entry into autos represents perhaps the most credible/formidable bear case for Tesla’s stock that investors have had to consider for some time,” analysts led by Adam Jonas wrote in a note Tuesday. Jonas gives Tesla a buy-equivalent rating with a $540 price target, about 15% below where it’s trading currently.

The iPhone maker getting into the vehicle market could also pose a threat to legacy automakers like General Motors and Ford Motor, which will have a hard time competing if “Apple were to really throw its weight around,” Jonas said.

For suppliers of electric, autonomous and connected-car systems, meanwhile, Apple’s plans “could very likely mean a significant inflection in the speed and magnitude of a wide range of investments,” he added. Lidar suppliers include Luminar Technologies and Velodyne Lidar rallied Monday after the report and continued to rise Tuesday.