$120/share offer from Amgen ( AMGN). It opened today at over $131. All the small speculators who follow merger and acquisition rumors the way others follow Los Angeles Dodgers slugger Yasiel Puig now have a new favorite. Onyx originally created sorafanib, sold as Nexavar, alongside Bayer, to treat advanced forms of kidney cancer. It was later found to work on advanced liver cancer and is now getting positive results with advanced thyroid cancer, according to a press release the two companies issued today. While Bayer was forced to license production to India last year, as Reuters reported, bringing costs there down from $5,500/month to $175, that doesn't seem to be a concern. Amgen got the bidding started over the weekend with an unsolicited offer of $120/share, valuing the company at close to $9 billion. (It was just south of $5 billion just last week.) Onyx CEO N. Anthony Coles turned the Amgen offer down at a meeting Friday, and the race was on. Analysts are now bidding up the company's price since they don't have to pay it. Prices of $148/share, $150/share and nearly $180/share were all tossed out to Forbes. The idea is that Onyx' costs are declining, that its sales effort can be pushed onto a larger company and that a second cancer drug called Kyprolis, or carfilzomib, which is presently seeking Food and Drug Administration approval, could also prove a blockbuster. There's also value seen in CEO Coles, who joined the company in 2008. At 52, he's seen as the kind of "big thinker" who might look very good running a bigger company, and the pharmaceutical industry is always looking for talent. The next step in all this is for the bears to start making a case. There are going to be concerns expressed about the cardiac risks of Kyprolis, and about the Indian patent case that cut the costs on Nexavar. Potential bidders including Pfizer ( PFE) and Bayer are going to act like poker players sensing a bluff, going quiet and coy in an effort to reduce speculation.