Why Did TMUS, CMCSA, JOBY Stocks Slump To 52-Week Lows Last Week?

T-Mobile US, Comcast and Joby Aviation fell to annual lows on Friday amid telecom sector weakness and Wall Street caution.

• TMUS stock plunged more than 13% at close on Friday after fears of telecom sector disruption following SpaceX’s formal entry. 
• CMCSA stock dipped more than 2%, also triggered by SpaceX’s Starlink concerns. 
• JOBY stock fell more than 5% after Barclays downgraded the company to ‘Underweight’ from ‘Equal Weight’ and slashed its price target. 

Shares of T-Mobile US Inc. (TMUS), Comcast Corp. (CMCSA) and Joby Aviation Inc. (JOBY) slipped to annual lows on Friday amid telecom sector developments and Wall Street caution. 

TMUS stock plunged more than 13% at close on Friday, its steepest single-day decline since its 2013 debut, after fears of telecom disruption following SpaceX’s formal entry into the sector. 

CMCSA stock dipped more than 2%, also triggered by SpaceX’s Starlink concerns. 

JOBY stock fell more than 5% after Barclays downgraded the company to ‘Underweight’ from ‘Equal Weight.’

T-Mobile Plunged On Starlink Fears

TMUS stock slumped to a 52-week low of $147.90 on Friday, posting its worst single-day decline in history after SpaceX (SPCX) formally entered the telecom space last week.

The company's shares were among the worst hit in the telecom space after Starlink announced it is adding up to 14 megahertz of paired spectrum in the 800 MHz band, sparking fears of sector disruption. 

However, shares recovered in the overnight session, climbing about 0.42% at the time of writing. 

Elon Musk said on social media that the move was “the last critical piece of the spectrum puzzle needed for SpaceX to provide complete phone coverage in America,” stoking fears that Starlink would eat into the market share of other telecom companies. 

However, retail sentiment around TMUS stock was ‘extremely bullish’ at the time of writing. The stock has lost 25% of its value year-to-date. 

Comcast Fell On Telecom Sector Slump

CMCSA stock fell to a 52-week low of $20.48 on Friday, capping six consecutive weeks in the red as a broader telecom selloff hit the company. 

SpaceX’s Starlink entering the telecom space rattled investors, who feared disruption would leave traditional players in the dust. 

Before the SpaceX announcement, Comcast struggled with broadband subscriber losses, aggressive competition, and weaker-than-expected cash flow.

Analysts project potential losses of more than 550,000 broadband subscribers through 2026. Meanwhile, competitors have slashed prices on high-speed internet plans, forcing Comcast to lower its own rates. 

Business softness and attendance slumps at Universal Studios theme parks have also dragged down its cash flows.

On Stocktwits, retail sentiment around CMCSA stock slipped from ‘bullish’ to ‘neutral’ over 24 hours. The stock has lost 25% year-to-date. 

Joby Aviation Attracts Wall Street Concerns 

JOBY stock fell to a fresh annual low of $5.23 on Friday, notching two weeks in the red amid growing concerns about the company. 

Last week, Barclays downgraded Joby Aviation and slashed its price target to $4 from $6, implying downside potential of about 26%. 

The firm said that it had rolled out coverage of the aerospace and defense group, saying the U.S. is in the "early innings of a modern-day industrial revolution." 

Meanwhile, the company has been struggling with high cash burn and insider selling. Joby Aviation spent $202 million on cash, cash equivalents, and short-term investments in the second quarter, bringing first-half 2026 cash use to $365 million, and expects to use another $385 million to $415 million in the second half of 2026.

Multiple high-ranking executives have also sold the company’s shares, with regulatory filings indicating that President of Operations Bonny Simi, CEO JoeBen Bevirt, and several other executives sold shares in recent weeks, largely to meet tax obligations. 

On Stocktwits, retail sentiment around JOBY stock was ‘extremely bullish’ at the time of writing. JOBY shares have declined nearly 62% year-to-date.

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