[statusgraph]

Yes, this has been used as a defense against insider trading accusations, sometimes unsuccessfully: https://en.m.wikipedia.org/wiki/Mosaic_theory_(investments)

[timthelion]

But isn't it equally true, that a mosaic of publicly known information could constitute non-public information? For example, the example I gave of analyzing satellite imagery of parking lots to predict Walmart sales numbers. Is that really fair?

[perl4ever]

I don't think you can deduce what is legally insider trading from an idea of what is "really fair". There really isn't much of a relationship. Matt Levine frequently writes about this.

[ryanlol]

You are allowed to trade based on non-public information. It doesn't matter if it's fair or not.

However, I'm not sure why this wouldn't be fair. More accurate valuations seem like a positive thing.