Just caught something interesting in the latest hedge fund filings. Looks like Bill Ackman's been making some notable moves in his AI playbook, and it tells us something about where sophisticated money is rotating right now.

So here's what happened: Pershing Square had been riding Alphabet pretty hard for the past few years. Solid AI exposure through Google Cloud and all their custom silicon work with Broadcom. But recently, Ackman decided to take some chips off the table from that position. We're talking an 86% reduction in Class A shares during Q4, while barely trimming the Class C holdings. Classic profit-taking move.

But the real story is where he moved that capital. This is pure Bill Ackman value investor playbook -- he's rotating into names that got beaten down while the market was obsessing over other things.

First up: Amazon. Ackman already had a position there from last April, but he just doubled down hard. Added another 3.8 million shares on top of the 5.8 million Pershing Square already owned. Why? Think about it. Both Amazon and Alphabet are building these vertically integrated AI ecosystems. AWS dominates cloud infrastructure at 28% market share, while Google Cloud sits at 14%. Both are designing proprietary chips to reduce Nvidia dependency. Amazon's got Trainium and Inferentia scaling up. They're exploring AI across consumer electronics, autonomous vehicles, robotics -- the whole stack.

But here's the thing: Alphabet had an absolutely ridiculous run over the last year. Amazon? Barely moved. So when you see Ackman rotating out of the one that's already had its party and into the one that's still being ignored, that's the value investor signal right there.

Then there's Meta, which might be the most misunderstood AI opportunity in megacap tech right now. Pershing Square just initiated a 2.7 million share position in Q4. Everyone's worried about Meta's ad-heavy model limiting AI upside, or concerned the company will waste AI budget like they did with metaverse spending. Fair concerns historically.

But look at the actual numbers. Their Advantage+ product is running at a $60 billion annual revenue rate. That's their AI-powered advertising suite driving real ROI improvements for customers. The scale here is massive -- 3.6 billion daily active users across Facebook, Instagram, and WhatsApp. If Advantage+ adoption accelerates across that entire ecosystem, Meta's advertising becomes stickier and more efficient. That's the AI opportunity people are sleeping on.

Here's what's wild: both Amazon and Meta just got hit with meaningful valuation corrections. Amazon sold off hard after announcing bigger capex plans for 2026. Meta's still in "prove it" mode. And now both are trading near their cheapest forward P/E ratios since this whole AI cycle started.

When institutional money like Bill Ackman is buying the dips in these names, it suggests they're thinking longer-term while the market gets distracted by near-term noise. For investors with real time horizons, following that playbook might actually make sense.