Sometimes the best trades are the ones you make before everyone else has to. That's the position two hedge fund heavyweights find themselves in after Carvana Co. (CVNA) secured its spot in the S&P 500, triggering mandatory buying from index funds and a premarket surge that made some very smart people even richer.

The Index Inclusion Payday

Carvana will officially join the S&P 500 within the next two weeks following Friday's quarterly rebalance announcement. The stock popped nearly 10% in Monday's premarket session, and the real buying hasn't even started yet. When passive funds that track the index are forced to purchase shares, that structural demand should provide additional fuel to a stock already riding high on improving fundamentals and expectations for lower borrowing costs.

The timing couldn't be better for Viking Global's Andreas Halvorsen and Coatue founder Philippe Laffont, who loaded up on Carvana shares during the third quarter. Halvorsen increased Viking's position to roughly 2.1 million shares, while Laffont boosted Coatue's stake to about 2 million shares, adding more than 200,000 shares during the quarter. Their average entry prices ranged from the mid-$260s to high $270s.

With the stock closing near $400 last week, the math gets interesting fast. Halvorsen is sitting on approximately $268 million in gains, while Laffont has racked up about $272 million in paper profits. That's a combined $540 million windfall, and the index-driven buying spree hasn't even begun.

The Comeback Nobody Saw Coming

The gains are even more impressive when you consider where Carvana was just eighteen months ago. The company was widely dismissed as a pandemic darling facing a harsh reality check, with bankruptcy speculation making the rounds. Today, it's outperforming major tech names and forcing passive fund managers to become buyers whether they like it or not.

The recent momentum got another boost in December when Wedbush analyst Scott Devitt upgraded the stock and issued a bold long-term forecast calling for Carvana to reach three million annual vehicle sales by 2033. That kind of optimism looks a lot more credible when you're being added to the S&P 500.

What Happens Next

For Halvorsen and Laffont, the trade is working exactly as planned. They positioned themselves early in the turnaround story, bought aggressively when the thesis was still controversial, and now they're watching the market mechanics work in their favor. If declining interest rates continue to support the narrative and index inflows materialize as expected, the next chapter could be even more profitable. These billionaires weren't chasing the rally — they were already holding their seats when the show started.