Verizon Communications, AT&T and T-Mobile got price-target cuts on Monday as investors remained concerned about the possibility that Amazon.com could offer wireless phone plans.

HSBC Global Research analyst Adam Fox-Rumley cut his price target on AT&T (ticker: T) to $19 from $21. He lowered his price target on T-Mobile (TMUS) to $165 from $185 and his call on Verizon to $39 from $42.50.

Shares of AT&T have fallen 17% this year to $15.34 while T-Mobile shares are down 5.4% to $132.40. Verizon stock has declined 11% to $35.01.

All three of these stocks tumbled on Friday following a report from Bloomberg that Amazon (AMZN) was in talks with those companies to potentially offer low-cost or even free nationwide mobile plans to Prime subscribers.

And even though the companies denied the report, Fox-Rumley cut his price targets on the telecom giants anyway to "price in some extra risk."

"Nerves abound, despite denials, that AMZN plans to enter U.S. mobile, threatening pricing backdrop and customer growth," Fox-Rumley said in a research note Monday.

"Amazon is unlikely to ever categorically rule out an option for the Prime bundle," he said. "The notion that mobile might be on the roadmap will be hard to put back in the box."

Still, Fox-Rumley thinks the selloff of telecom stocks following the report was overdone. He maintained Buy ratings on AT&T and T-Mobile and a Hold rating on Verizon.

Not all analysts are even convinced Amazon is working toward offering a wireless plan to Prime subscribers. BofA Securities analyst Justin Post said in a research note Monday that because Amazon is constantly looking at expanding its Prime services and exploring multiple opportunities to attract Prime members, a report about possible discussions wasn't surprising to him.

"However, offering subsidized wireless services at a loss seems unlikely as Amazon appears to be gaining share in U.S. online retail, Amazon is focused on retail margin improvement, and Amazon already has high Prime household penetration in the U.S.," Post said.

He rates Amazon as a Buy with a $139 price target. The shares were at $125.46 on Monday morning.