This study examines how temporary intermediary organizations enable episodic coordination across spatially segmented capital markets. Using accelerator cohorts as an empirical setting, we show that greater geographic diversity among participants is associated with a higher likelihood of fundraising during the accelerator period and with the formation of cross-regional investment ties, particularly with investors located in peers’ home regions. These effects are concentrated around the investor pitch event, indicating that the benefits of geographic diversity arise from short-lived opportunities for network mobilization rather than from durable capability accumulation. The findings highlight how layered, time-bounded organizational arrangements can momentarily relax spatial constraints without altering underlying, path-dependent institutional structures, offering an explanation for how coordination occurs across regions in industrial systems.