Soroban Q1 2026: 45.44% Microsoft Bet

TL;DR: Soroban Capital Partners LP turned its 2026Q1 Form 13F-HR into a concentration event: a $51.80B reported 13F book, MSFT at 45.44%, META at 23.64%, and AMZN at 11.41%. The filing, report dated 2026-03-31 and filed 2026-05-15 under accession 0000919574-26-003541, reads less like a diversified hedge fund snapshot and more like a deliberate platform-tech wager.

Soroban Capital Partners LP, the active hedge fund associated with Eric Mandelblatt, reported 30 holdings in the SEC filing and 27 current positions in the canonical 13F Insight brief. The key signal is not just size. It is that three names dominate the entire visible 13F exposure, with the rest of the book acting as a narrow supporting cast rather than a conventional long equity sleeve.

The hook: Microsoft alone became almost half the 13F

The strongest data point is impossible to bury: Microsoft (MSFT) was Soroban's largest reported holding at $23.54B, 63.58M shares, and 45.44% of the Q1 2026 portfolio. For a fund already known for concentrated long/short equity work, that is the filing's message. The 13F is telling readers where the active risk sits.

The first chart shows why the headline belongs to concentration. MSFT towers over META, AMZN, and every sub-$2B position. Meta Platforms (META) was still massive at $12.24B and 23.64%, while Amazon (AMZN) added another $5.91B and 11.41%. After those three, the portfolio drops to Mastercard at $1.23B and TransDigm at $992.3M.

What the top-five mix says about Soroban's Q1 posture

Soroban did not spread its reported risk evenly across 27 current positions. The Q1 file shows a top-heavy stack: MSFT, META, AMZN, Mastercard (MA), and TransDigm (TDG). That combination puts mega-cap platform technology at the center, then layers in payments and aerospace compounder exposure.

The concentration chart makes the decision visible. MSFT accounted for 45.44%, META for 23.64%, AMZN for 11.41%, MA for 2.38%, and TDG for 1.92%. The remaining diversified tail was 15.21%. In practical terms, Soroban's Q1 2026 13F was not asking investors to parse dozens of equal-weighted ideas; it was asking them to evaluate a small number of very large convictions.

The reported 13F value surge changed the scale of the signal

The AUM history adds the second layer. Soroban's reported 13F value moved from $14.33B in 2025Q4 to $51.80B in 2026Q1, a +261.4% quarter-over-quarter move in the canonical brief. That follows an already volatile path: $10.25B in 2025Q2, $5.15B in 2025Q3, and $14.33B in 2025Q4.

This is why the Q1 filing matters beyond the top-ten table. A large reported 13F value can reflect portfolio construction, option exposure reported in 13F terms, and security-level price moves, so it should not be read as a full balance sheet. But the SEC-reported snapshot still says Soroban made the visible long book far larger and far more concentrated around a small platform-tech core.

Position notes: the supporting cast is selective

Below the three mega-cap anchors, Soroban's largest supporting positions were MA at $1.23B, TDG at $992.3M, Domino's Pizza (DPZ) at $895.3M, Visa (V) at $895.0M, Equifax (EFX) at $753.5M, S&P Global (SPGI) at $718.2M, and TSM at $652.8M. Those positions are not filler; they show a preference for scalable, high-quality franchises after the platform-tech core.

Rank	Holding	Value	Weight	Shares
1	MSFT	$23.54B	45.44%	63.58M
2	META	$12.24B	23.64%	21.40M
3	AMZN	$5.91B	11.41%	28.37M
4	MA	$1.23B	2.38%	2.46M
5	TDG	$992.3M	1.92%	856.2K

How to read this filing

The clean read is that Soroban's Q1 2026 filing is a concentrated active-manager signal, not a passive index footprint. The fund's filerType is not classified as passive, market maker, custodian, or fund-of-funds in the platform data, and the portfolio shape matches an active conviction book. For readers comparing hedge fund behavior, the useful question is not whether Soroban owned MSFT, META, and AMZN. It is how much of the reported book those three absorbed.

For follow-up work, compare Soroban's filer page with each underlying stock page. Microsoft institutional ownership shows the crowd around the biggest position, while Meta holder data and Amazon's 13F holder base help separate Soroban's conviction from broader mega-cap ownership.

FAQ

What does Soroban Capital hold in Q1 2026?

Soroban Capital's Q1 2026 13F was led by MSFT at $23.54B, META at $12.24B, and AMZN at $5.91B, with MA and TDG rounding out the top five.

How large was Soroban Capital's 13F portfolio in 2026Q1?

Soroban Capital reported $51.80B of 13F value for 2026Q1, based on the canonical 13F Insight brief and the SEC filing report dated 2026-03-31.

Why is Soroban Capital's Microsoft position important?

MSFT represented 45.44% of Soroban's Q1 2026 13F portfolio, making it the dominant position and the clearest signal in the filing.

Is Soroban Capital a passive index fund?

No. Soroban Capital Partners LP is treated here as an active concentrated hedge fund, not a passive index fund, market maker, custodian, or fund-of-funds.