Efficient marketplaces for the exchange of intellectual property (IP) are crucial for firms' ability to create value from their knowledge assets. However, only a few studies, mostly focused on patents, have investigated how IP marketplaces actually operate. The present article contributes to filling this gap in our knowledge. Using a study of 38 UK-based firms in the information and communication technology (ICT) sector, we investigate the obstacles they experience when exchanging different types of IP, both proprietary (patents and copyright) and non-proprietary (open source and trade in non-patented technology). We find that IP marketplaces - including markets for patents - do not work smoothly as channels for value creation processes, as perceived in mainstream economics and coupled government policies, but suffer from several institutional failures, related to market search problems (e.g. finding users or owners of IP or "best IP"), lack of IP market transparency (e.g. in relation to novelty and value), difficulties in contract negotiation (e.g. price) and enforcement, problems with regulations and with firms' practices.