When Stage 2 failed to garner enough bids to top the clearing cost, the amount of spectrum offered was reduced and Stage 3 begun. But this stage drew $19.7 billion with a clearing cost of $40.3 billion. That means bidders like Verizon, T-Mobile and AT&T bid just 49% of the clearing cost.
So now the FCC will meet with the television stations that own the spectrum, and will reduce the amount offered once again. A new clearing cost will be computed and Stage 4 is expected to start on December 13th. If the clearing cost is topped, the auction moves to the final stage. If not, Stage 5 awaits.
source: FCC via FierceWireless