Demand for spectrum in the FCC's forward auction took a big drop in Round 25.

In most of the top markets, supply and demand were on par, suggesting the FCC may have started to find its spectrum price points and may soon have to lower its spectrum sights and return to the reverse auction at a lower clearing target.

The total bid in round 25 was $22,985,963,900, vs $22,704,101,100 in Round 24, or an increase of only a little more than 1%, while the FCC was raising prices by 10%.

The FCC divided the spectrum into 416 partial economic areas, and in only a few does demand exceed supply. The auction won't end until there are no markets with excess demand, so money could still move around.

In top market New York, round 22 had seen 19 licenses bid for with only 10 available. In round 25, only 10 licenses were bid for. The story was the same in many top markets.

In fact, in eight of the top 10 markets, supply no longer exceeded demand, with Los Angeles -- at bids for eight licenses with only five available -- and Houston with bids on 11 licenses with 10 available -- the only exceptions.

But the auction won't close successfully unless the net figure for bids -- the total minus bidding credits and discounts -- meets or beats $88.3 billion. The Round 25 figure was only a little more than a quarter of that at $22,320,000.

One spectrum watcher who conceded a second stage is likely said that prices should go up in the next round when the FCC reduces the supply of licenses.

Broadcasters were willing to give up 126 MHz in the reverse auction, but it looks like wireless buyers won't be covering the FCC's $86 billion clearing cost.

But the auction was always set up for multiple rounds. The next clearing target is 114 MHz. The FCC will go back to broadcasters, continue the reverse auction at that, come up with a clearing cost, then take a second crack at a forward auction. 

With a couple of dozen rounds of the forward portion of the FCC spectrum auction in the books, the bidding stood at $22,704,101,100, up just under $700 million from round 23's $22,077,875,100.

The magic number, which is the bid total minus discounts and bidding credits, stood at an even $22 billion.

That is the number that must be quadrupled (plus a bit) to the $88,379,558,704 that will cover payments to broadcasters and the cost of the auction and post-auction TV station repack.

Demand in the top two markets -- New York and Los Angeles -- continued to drop, though in both cities demand still exceeded supply. In both cases, the FCC was still getting its asking price, which it is increasing by 10% in each round.

Related:Spectrum Auction Bids Up Over $860M After Round 22

If the FCC does not raise enough to cover the $88-plus billion figure, it will move to stage 2 of the auction, where it will lower the spectrum clearing target from 126 MHz to 114 MHz, continue the reverse auction at that lower figure--winnowing out some of the broadcasters that would have been paid at the higher spectrum-clearing total--then try to cover that new figure in a forward auction.

The FCC has nine possible spectrum clearing targets down to a low of 42.