Here's a deal that no one knew about as gauged by almost ZERO options trading in CVNS. It's a $1.3 bln cash deal with a near $8/shr premium. CSC to Acquire Covansys for $34.00 per Share. This is why it is so important to understand that while rumors can move the options markets, often times the real deals happen without any indication in the options markets. Of course, many times things get leaked a la 'loose lips sink ships'.
The system of looking at trading volumes in options vs open interest is not a fool proof one in the M&A game - even in the earnings game. There nothing noble about it; it's still all guessing and grasping for a buck unless you have insider info.