Shares of spectrum and intellectual property company Straight Path (STRP)  shot higher yet again on Monday after the company said an unnamed suitor had upped its bid for the second time, this time to $184 per share in stock, or $3.1 billion. The company said its board considered it superior to a prior agreement with AT&T (T - Get Report) .

Straight Path jumped more than 26% to $204.25 per share before Monday's open, topping the current sale price and suggesting that Wall Street expects the final price to be even higher. Since AT&T's bid for Straight Path was first announced in early April, shares of Straight Path have more than quintupled.

AT&T now has three days to respond to the bid from the unnamed multi-national suitor, which is reportedly Verizon (VZ - Get Report) . The telecom has declined to comment.  

According to Straight Path, the unnamed suitor topped its own bid of $135.96 per share, or $2.3 billion in total, which Straight Path named superior to AT&T's bid on May 3. Straight Path did not disclose details about the intervening bids between AT&T and the rival that have pushed the sale price higher. 

Straight Path has been rocketing since AT&T said it would buy the company for $95.63 per share, valuing the total company at $1.6 billion, on April 10. The company's close prior to the original AT&T deal was $36.48, meaning the stock has more than quintupled since bidding broke out.

AT&T has touted the value of Straight Path's spectrum for 5G services, the next generation of wireless broadband that will feature higher capacity and will ultimately connect smart cars, urban infrastructure, medical devices and other parts of the Internet of things-if the technology lives up to the hype.

Straight Path, which telecom and payments company IDT (IDT - Get Report) spun out in 2013, was on the market after a scolding earlier this year by the Federal Communications Commission.

The FCC announced a potential $100 million fine against Straight Path in January, for "squatting" on wireless licenses, or failing to meet government requirements to deploy services on acquired spectrum. Straight Path would pay $15 million up front, and another $85 million would come due if the company were not sold by year's end. The FCC also stands to collect 20% of the sale price.

Glen Allen, Va.-based Straight Path hired Evercore to shop itself back in January.

Meanwhile,  Globalstar  (GSAT - Get Report)  gained nearly 8% before Monday's open to $1.92. The satellite communications company owns wireless spectrum that the FCC recently approved for some wireless services.