Just spotted something interesting in the latest 13F filings. Billionaire Stephen Mandel completely cleared out Lone Pine Capital's entire Meta position in Q4 — we're talking 1.3+ million shares that were worth nearly a billion dollars just months earlier.

Here's what caught my attention: Meta had been a solid core holding since mid-2023, and the stock more than doubled over that stretch. So yeah, profit-taking makes sense on the surface. But the timing is worth digging into. Mandel dumped the whole position right after Meta's AI capex guidance disappointed in late October. Zuckerberg keeps ratcheting up the spending quarter after quarter, and apparently that was enough to spook the fund.

The irony? Meta's social media properties still command premium ad rates, and if those AI investments pay off in a few years, this could end up being a sale Mandel regrets. But I get the logic — when you run a fund with only a 16.5-month average hold period, you don't wait around hoping for the long play.

What's more interesting is what replaced it. Taiwan Semiconductor Manufacturing is now Lone Pine's number one holding by market value. Even though Mandel's actually been trimming the TSMC position over three years, the stock's parabolic move has pushed it to the top spot anyway.

The AI angle here is obvious — TSMC is absolutely crushing it on GPU demand right now. Their chip-on-wafer capacity is expanding like crazy, and they've got solid pricing power because supply can't keep up. But TSMC wasn't built on AI hype alone. They're still the backbone for smartphones, computers, and IoT stuff. The valuation's reasonable too — forward P/E around 21 for a nearly 2 trillion dollar company projecting 24% sales growth.

What's telling is that even while reducing his stake, Mandel's still got TSMC as the crown jewel. That's the kind of conviction move you see from someone who's been in the game a long time. The semiconductor play looks way more attractive to him right now than banking on Meta's AI ambitions.