Last October I wrote a piece about how Silicon Valley’s usual optimism had been replaced by fear, and that private market valuations were beginning to contract. It became my most-read post of 2015, and elicited two broad buckets of reaction:

(1) Yup.

(2) Where’s the data, you worthless hack?

The first group either was seeing the shift first-hand, or trusted that my reporting was based on conversations with dozens of people involved in such transaction. The latter was fixated on this admission, from within the post:

To be clear, I don’t have data backing any of this up. As the banker said, it’s too new a phenomenon and, of course, there will be notable exceptions.

Here was some of the blow-back:

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Since then, it has become conventional wisdom that private market valuations have indeed pulled back (particularly for later-stage companies), and that unit economics have supplanted top-line revenue growth. Evidence includes a large rash of mutual fund mark-downs, plus “down rounds” for such companies as Foursquare and Jawbone. And the current stock market swoon ― which has been particularly harsh on VC-backed tech companies that went public over the past two years ― is also taking its toll.

Moreover, Q4 saw fewer later-stage deals and dollars than in any of the prior four quarters (per Pitchbook), and fewer up rounds than in the prior two quarters. Yes, there are still new unicorns being minted ― but the general trend-lines no longer look like rocket ships.

Right now, you probably think the purpose of my post is something akin to “nah nah nah nah… I told ya so.” But it really isn’t. Instead, it’s to highlight what has become has become Silicon Valley’s religious adherence to numerical data at the sake of real-life observation. Rather than “I know it when I see it,” we’ve moved into “I know it when someone has calculated it.”

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While data ― big and small ― certainly has enormous value, it is a bit odd that the ‘disruptive’ community so regularly relies on lagging indicators when it comes to its own financial health. We see it not only in this discussion, but also in how venture capital firms raise/deploy money in lockstep with macro economic cycles. I’m not saying numbers should be ignored, but rather than they often require context.

If you don’t peek up from your real-time dashboards and spreadsheets once in a while, you may miss what’s really going on. And then it will be too late.