they have a cystic fibrosis combo.g buy. >> what dealer are options are traders betting on? we go to the sherlock of puts and calls, david ka russo of volatility. >> they mentioned nine potential takeover candidates and four of them i'll mention right now, biomarin and vertex and ale ale. on april 9th they traded six times their average daily call volume. yesterday kben, three times the average call volume. you might think advanced earnings is what this is about. what we were seeing is a lot of activity in the july 80 calls and those are about $9, a 30% move to the upside on a stock that usually moves about 3% on earnings and pretty clear that isn't what they were betting on and going out a little further than the earnings date. it seems if anybody is betting on an upside move, it looks like vertex is the one. >> do you use unusual activity as your guide to what could be the next target? >> in a space like this, it can be. most investors at home never know when the dates are or what the probabilities of some sort of bi