Instacart got a haircut. The company sliced its valuation by nearly 40% from $39 billion to $24 billion — despite the fact that it saw 30% year-over-year growth last year. And Instacart is not the only high-tech company trimming its valuation. So what’s going on? In this episode of Startup Insider, Vin Narayanan and Andy Gordon discuss why Instacart trimmed its valuation, what this means for startup valuations in general, what trends investors can…