The Window Problem
Market windows don't close all at once. They narrow gradually, then suddenly. The signal you're looking for is when major players start circling adjacent space.
Market-Research
The Competitor as Proof
Finding a funded competitor in your space feels like bad news. It usually isn't.
The Named Gap
There are many ways to infer that a market gap exists. Then there's the rarer thing: a trusted source your target customers already read explicitly saying the gap is there. These are not the same signal.
The Tier Problem
Not all gaps are the same. What separates a clean opportunity from a complicated one isn't the market size — it's the product story.