Venture capitalist Fred Wilson has invested in companies including SoundCloud and Turntable.fm, and has become an insightful and often deliberately-spiky observer of the technology industry. So what’s making him “grumpy” this week? Well, call that this year: burn rates. “Burning cash. Losing money. Emphasis on the losing,” as he put it in a blog post yesterday. “And they are indeed sky high all over the US startup sector right now. And our portfolio is not immune to it. We have multiple portfolio companies burning multiple millions of dollars a month. Thankfully its not our entire portfolio. But it is more than I’d like and more than I’m personally comfortable with.” Wilson says he’s “made myself a pain in the ass to more than a few CEOs” with his demands that they rein in risky spending plans and take a second look at costly long-term leases. “At some point you have to build a real business, generate real profits, sustain the company without the largess of investor’s capital, and start producing value the old fashioned way,” he wrote.