Rambus (RMBS) is bucking the bearish trend and options trading is brisk after the chipmaker signed a comprehensive agreement with Samsung. Under the plan, Samsung will invest $200 mln. RMBS is up $2.28 to $23.41 and 33K options traded, or 6X the expected for the first hour of trading. The action is scattered, but like yesterday (when chatter about a legal settlement was making the rounds — see 2:55 color), front month calls with strike prices ranging from 19 to 30 are actively traded. Implied volatility is falling for a second day as well, down 14.4 percent to about 66 (from 87 Friday).