Key points include Tesla and Alphabet both announcing increased investments in artificial intelligence, leading to higher capital expenditures. Some of Google's AI investments are beginning to yield returns, with its second-quarter cloud revenue surging 82% year-over-year. Tesla is concurrently investing heavily in robotics and semiconductor ventures.

During Thursday's pre-market trading session in the US, shares of both Alphabet and Tesla declined. The companies disclosed plans to increase spending related to AI, sparking market concerns that the AI boom is driving up costs and heightening investor risk aversion.

In pre-market trading, Alphabet shares fell approximately 4%, while Tesla Motors shares dropped more than 5%.

Both companies reported earnings on Wednesday, revealing negative free cash flow for the second quarter.

Alphabet (Google's parent company) raised its full-year capital expenditure guidance, now expecting annual spending between $195 billion and $205 billion, while also warning of further increases in 2027. The previous guidance range was $180 billion to $190 billion.

Tesla Motors reported a 142% year-over-year surge in second-quarter capital expenditures to $5.79 billion. The company estimates its total capital investment for the year will exceed $25 billion.

Executives from both companies sought to reassure the market and alleviate investor anxiety over the substantial spending.

Tesla Motors CEO Elon Musk stated during Wednesday's earnings call, "This year is a year of significant capital investment. I am confident that all current investments will yield exceptionally high returns, potentially setting a record for the best return on capital invested in the company's history."

Musk detailed where the funds are being directed, highlighting two long-term projects: in-house semiconductor development and the Optimus humanoid robot. Tesla's earnings presentation noted that the first-generation Optimus production line is under construction and will soon commence operations.

Alphabet CEO Sundar Pichai explained that the primary driver for the increased spending is the accelerated expansion of computing capacity to meet rising AI demand. The tech giant has repeatedly stated that its current computing resources are insufficient to handle the surge in AI-related business.

The negative impact of the heavy spending partially offset positive highlights from both companies' earnings reports.

Several of Google's AI investments are starting to pay off: Google Cloud revenue jumped 82% year-over-year to $24.8 billion, significantly exceeding market expectations.

Tesla Motors core automotive business remained solid, with automotive segment revenue rising 23% year-over-year to $20.52 billion.