"Flow in AT&T and Verizon, particularly in the options, has become more balanced [when] it used to be very bullish," Stacey Gilbert, head of derivative strategy at Susquehanna, said Monday on CNBC's "Power Lunch."
In addition, the Vanguard ETF tracking telecom stocks (which largely just tracks the aforementioned two) has seen some $500 million worth of inflows this year, according to ETF.com. But as Gilbert points out, those flows are drying up.
"I think the love fest is dying here," she said.
Among the parties that have departed the telecoms are Warren Buffett's Berkshire Hathaway, which sold out of its AT&T holding as of the end of the first quarter, according to a filing released Monday.
Rich Ross, a technical analyst with Evercore ISI, said investors would do well to follow Berkshire out of the name. According to his work, AT&T's chart has already made a "double top," indicating that a drop could be ahead.