2015 wasn’t the best time for an ad tech company to tap the public markets. And 2016 seems like it will be equally uncertain – one need only look at the strange ongoing saga of AppNexus to see that. But it’s an overstatement to say that all ad tech companies are in trouble, according to Brian Andersen of LUMA Partners. He will speak Wednesday at AdExchanger’s Industry Preview conference about the ad tech-mar tech convergence and examine what the future holds. Ad Exchanger