This article draws on interview data from California's Silicon Valley to explore the role of local business attorneys in shaping the market for high-technology start-up financing. Far from exerting a disruptive or disputatious influence on business relations, Silicon Valley lawyers actively facilitate the functioning of the region's venture capital sector. In particular, attorneys intervene in the start-up process to absorb, suppress, and avert crucial uncertainties that might otherwise elevate transaction costs, imperil economic activity, and foster interorganizational discord. Local law firms moderate the hazards of new-company financing in at least three distinct ways: (1) by directly absorbing economic uncertainties in individual transactions; (2) by constructing, preserving, and reproducing normative and cognitive understandings within the community as a whole; and (3) by incorporating these local practices into the external legal regime.