Macy's Inc (NYSE:M) is 16.1% higher at $20.92 this morning, after Arkhouse Management revised its buyout offer. Specifically, Arkhouse and Brigade Capital Management raised their buyout offer for the department store giant to$24 per share, or about $6.6 billion. Call traders are piling on M after the news. Already, more than 26,000 bullish bets -- or 5 times the intraday average volume -- have crossed the tape, compared to just 12,000 puts. Most popular by far is the April 21 call, followed by the 23 call ...