We extend the knowledge-based view with a new typology and its application to post-IPO firm performance. The typology categorizes knowledge development activity along the dimensions of familiarity (whether the firm has experience with the knowledge or it is new) and source (whether the firm creates it independently or with partners). We use this typology to determine direct and interaction effects of knowledge development activity on survival, RoA, and Tobin's q of newly public firms. Using a sample of 1,056 high-technology manufacturing IPOs in 1990–2005, we find that focused, internal knowledge development correlates with higher performance. We also find a positive interaction effect in combining focused, internal and diversifying, alliance-based knowledge development, and a negative interaction effect in combining diversifying, internal and alliance-based knowledge development. Copyright © 2013 John Wiley & Sons, Ltd.