Just caught Apple's latest earnings and there's something worth unpacking here. Tim Cook just announced they hit 2.5 billion active devices - a new record. That's a massive installed base, and honestly it's one of the biggest competitive moats in tech right now.

The services business is firing on all cylinders too. Hit an all-time high of $30 billion in revenue, up 14% year-over-year. This is the part that actually matters long-term because once you've got people locked into that ecosystem, the switching costs become real. Hardware plus software together creates something that's genuinely hard to replicate.

But here's where it gets interesting. Buffett has been quietly selling. Since Q4 2023, Berkshire Hathaway has been a net seller in 6 out of 8 quarters. They've gone from over 900 million shares down to 238 million. That's not a small trim - that's a significant reduction. When one of the greatest investors ever starts lightening up, you have to ask why.

Valuation is almost certainly part of the story. Apple's trading at a P/E of 34.1 right now. That's not cheap. For context, that's pricing in a lot of future growth, and the question becomes whether the company can deliver on those expectations, especially in AI where they've been slower to move compared to competitors.

So you've got this interesting dynamic. The business fundamentals are genuinely strong - that installed base of a trillion-dollar ecosystem is no joke. But the valuation is stretched, and when you see someone like Buffett taking profits after years of holding, it's worth at least considering what that signal might mean. Not saying Apple is going anywhere, but at these prices, the risk-reward equation has definitely shifted.