With this morning's news that the U.S. Justice Department is opposing the proposed merger between beer giant Anheuser-Busch InBev (ADR) (NYSE:BUD – 87.75) and Mexican beer concern Grupo Modelo SAB de CV (USA) (GPMCF), put volume on BUD exploded, jumping to 20 times what is typically seen on an intraday basis.

The most popular strike is the front-month February 87.50 put, which has seen more than 1,300 contracts cross the tape so far today, with the majority of those going off at the ask price. With volume exceeding open interest, it is likely at least some of these trades were bought to open. Given the volume-weighted average price (VWAP) of $1.31, the stock would have to drop to $86.19 (strike less VWAP), or 1.8% from its current levels, by the expiration date of Feb. 15 for these puts to be profitable.

Earlier today, Justice Department regulators cited competitive concerns over the proposed $20.1 billion merger, saying that the deal would substantially reduce competition in North America. BUD's Bud Light brand is the most popular in the U.S., while Modelo's Corona Extra is the country's most popular import in the U.S.

The news has led to a drop of more than 7% in BUD shares today, putting the halt on what had been a strong technical run. Before today, BUD had climbed more than 19% since the end of July through Wednesday, as the merger had gotten approval from other international regulatory bodies.

But the new infusion of bearish bets is nothing new for BUD. The equity's 10-day International Securities Exchange (ISE), Chicago Board Options Exchange (CBOE), and NASDAQ OMX PHLX (PHLX) put/call volume ratio stands at 2.78, in the 90th percentile among readings taken in the previous 12 months -- indicating a higher-than-normal bearish stance among short-term traders.