The FCC paused its millimeter-wave (mmWave) spectrum auction for the holidays, allowing bidders to take a break from their billion-dollar gambles. Action in the auction -- which is nearing $6 billion in total bids -- is scheduled to resume Jan. 6.

Already the auction has surpassed some initial estimates that pegged total bids topping out at $3 billion.

However, it appears that the event is slowly cruising toward a finish. "Incremental gross bids by round had been climbing uphill, but then started going downhill fast in recent rounds," noted the analysts at Wall Street research firm Raymond James in a note this weekend to investors.

Figure 1: (Source: Raymond James)

Simillary, spectrum expert Stephen Wilkus of Spectrum Financial Partners pointed out that the total amount of bids in the auction grew 20% throughout the first few rounds of bidding in the FCC's ongoing auction, but in the event's most recent round that rate slowed to just 3%. This indicates that "capital reserves are now limiting new bidding," Wilkus wrote in a lengthy assessment of the event on LinkedIn late Friday.

There's little doubt that Verizon, AT&T and T-Mobile are driving much of the action in the FCC's latest mmWave spectrum auction. As Wilkus points out, there are 35 qualified entities participating in the FCC's auction, but 17 of those are small businesses or rural carriers unlikely to spend much money. Companies such as Charter Communications and Comcast didn't even register to participate in the event. The FCC isn't disclosing the identities of the bidders during the auction, and will only do so after the auction has finished.

However, the FCC is releasing some information about the auction, which will restart next year with round 27. For instance, the agency is showing the geographic locations where bidders are competing for mmWave spectrum licenses.

Figure 2: (Source: Stephen Wilkus of Spectrum Financial Partners)

Perhaps not surprisingly, much of the action centers on the spectrum licenses covering dense urban areas like Los Angeles and New York City. That's likely due to the fact that transmissions in mmWave spectrum often can only travel a few thousand feet at most, making it difficult for operators to use mmWave spectrum to cover large rural areas.

Dubbed Auction 103, this is the FCC's third mmWave spectrum auction, and by far its biggest, both in terms of the money raised and the amount of spectrum available. The FCC's Auction 101 for 28GHz spectrum licenses raised $703 million in total bids, while its Auction 102 for 24GHz licenses raised $2 billion in bids. Verizon, AT&T and T-Mobile spent the most money on spectrum licenses during the FCC's two previous mmWave spectrum auctions.

Operators including Verizon, AT&T and T-Mobile are using mmWave spectrum for 5G.

— Mike Dano, Editorial Director, 5G & Mobile Strategies, Light Reading | @mikeddano