Benchmark general partner Bill Gurley called on Silicon Valley's "unicorn" start-ups to grow up, get profitable or go public. : Influential venture capitalist Bill Gurley says it's time for Silicon Valley's "unicorns" to grow up. Gurley, a partner at venture capital firm Benchmark, spoke in an interview on CNBC's "Squawk Alley" on Friday, following the IPO of Stitch Fix, an e-commerce fashion start-up backed by his firm. Stitch Fix priced shares at $15, below its expected range, but the stock is up about 13 percent in its first day of trading.