Andreessen Horowitz Bets $180 Million on Newly Hatched Startups

A few weeks ago, about 150 people gathered in the courtyard of Paris Hilton’s $63 million chateau-style mansion in the Los Angeles enclave of Beverly Park. They sipped cocktails, picked at poolside sushi and played poker while a DJ mixed beats. What looked like a Hollywood soiree was, in fact, a networking night for participants and alumni of Speedrun, the relatively unknown startup accelerator run by venture capital firm Andreessen Horowitz.

The celebration in SoCal signals a new approach for Andreessen Horowitz, often called a16z. The firm has traditionally waited until startups had some traction before writing checks. With Speedrun, ...