More and more early-stage startups are seeking accelerators to help them quickly identify their best growth strategy and launch them with a plan to achieve it. Over the past few years, many new accelerators have appeared that target specific types of startup and deliver a more rewarding experience. Three distinct types of accelerators have emerged. One type aligns with startups targeting specific markets (“vertical accelerators”). A second type aligns with startups targeting specific technologies and products (“horizontal accelerators”). Accelerators operated by specific companies (“corporate accelerators”) make up a third type. These focused accelerators develop a strong program around their theme, build ties to a theme-aligned mentor network, and solidify relationships with investors actively engaged in the accelerator’s theme. The resulting accelerator ecosystem is better able to assist these specific types of startups, optimizing the probability of success for the startup and the accelerator.