Ryan Vlastelica

(Bloomberg) -- Nvidia Corp.'s sinking stock valuation is sending a warning signal about the chipmaker's prospects for maintaining its booming profit growth.

Netflix Inc. received its second downgrade in less than a week on Tuesday, with Wall Street analysts concerned about its lack of big hits and competition from YouTube.

Part of the problem is that Nvidia's profitability is under pressure, in large part due to rising costs for key components like memory chips. Nvidia's gross margin was a whopping 75% in the second quarter, but is projected to shrink to less than 72% in the fourth quarter before rebounding in the coming quarters, according to the average of analyst estimates compiled by Bloomberg.

Netflix Inc. received its second downgrade in less than a week on Tuesday, with Wall Street analysts concerned about its lack of big hits and competition from YouTube.

Microsoft Corp. was upgraded to buy from hold at Stifel, in what represents a vote of confidence from one of the few Wall Street’s firms that were cautious on the stock after its lagging run this year. The shares gained nearly 1% in pre-market trading.

Meta Platforms Inc. is finally seeing the stock breakout that beleaguered bulls had been banking on.

(Bloomberg) -- Meta Platforms Inc. is finally seeing the stock breakout that beleaguered bulls had been banking on. Most Read from Bloomberg

Meta Platforms is finally seeing the stock breakout that beleaguered bulls had been banking on.

Shares of cybersecurity companies have soared in recent months on bets that the threats posed by cutting-edge AI models will be a boon for their businesses. But some of the stocks have run up so much that investors are questioning whether they've gone too far.

The Facebook parent’s shares had jumped 36% in September through Thursday’s close following the release of its Muse personal AI assistant, which has risen quickly to the top of app charts and muffled concerns that heavy spending on AI won’t pay off. The stock is on pace for its best month since July 2013 and within striking distance of joining an elite group of companies worth at least $2 trillion.