Kevin O'Leary has a message for startup founders, and it's not particularly gentle: your financial projections are wrong.

The entrepreneur and investor took to X on Sunday with a pointed warning about the fastest way businesses crash during their first year. The culprit? Founders who actually believe their own numbers.

Here's the problem, according to O'Leary: every founder creates what's known as a "hockey-stick forecast"—those beautifully optimistic growth projections that shoot upward like, well, a hockey stick. And they're almost never accurate.

So what should founders do instead? O'Leary's advice is refreshingly practical: "Stay flexible, pivot, and preserve cash until you know the real velocity of your business."

It's simple wisdom that cuts to the heart of early-stage survival. Cash flow keeps businesses alive, and adaptability keeps them relevant. You can't predict exactly how your business will perform, but you can make sure you have enough runway to figure it out as you go.