---
title: "Susquehanna Owns B of UNH: Market Maker 13F Decoder"
type: learn
slug: market-maker-13f-susquehanna-jane-street-citadel-options-inventory
canonical_url: https://13finsight.com/learn/market-maker-13f-susquehanna-jane-street-citadel-options-inventory
published_at: 2026-05-15T05:16:47.107Z
updated_at: 2026-05-15T05:16:50.619Z
author: Sarah Mitchell
author_title: Education Editor
author_url: https://13finsight.com/authors/sarah-mitchell
word_count: 1037
locale: en
source: 13F Insight
---

# Susquehanna Owns B of UNH: Market Maker 13F Decoder

> Susquehanna International Group holds $10.34 billion of UnitedHealth at 1.19% portfolio. Jane Street, Citadel Advisors, CTC, and Wolverine Trading hold similar large positions across high-options-volume stocks. These are not conviction positions — they are options inventory.

When you look at the 13F holder table for almost any high-options-volume US stock — UnitedHealth, MicroStrategy, Tesla, Nvidia, GameStop, CrowdStrike, Coinbase, and many others — you will see Susquehanna International Group, Jane Street Group, Citadel Advisors, CTC LLC, Wolverine Trading, or similar firms listed in the top 10 or top 20 holders at meaningful dollar values. UnitedHealth shows Susquehanna at $10.34 billion / 1.19% portfolio. MicroStrategy shows Jane Street at $3.47 billion, Citadel at $3.28 billion, CTC at $3.37 billion, Wolverine at $2.94 billion — combined market-maker inventory of $12.66 billion in a single stock. CrowdStrike, Coinbase, Tesla, and other high-options names show the same pattern. These are not conviction positions. They are options inventory held by market makers to facilitate the underlying options market. Reading them as institutional ownership signals systematically misreads what the 13F is showing.This guide explains how market-maker 13F inventory works, why it appears in the top of holder tables, how to identify it consistently, and what reading rules apply. The platform's filer-type classification system already filters out classified market makers (Susquehanna, Jane Street, market-maker-tagged Citadel sleeves) from smart-money surfaces — but reading raw 13F holder tables requires the same filtering manually.How market-maker 13F inventory worksUS options market makers operate by quoting two-sided markets in listed options contracts. To hedge the resulting directional exposure, they buy or sell the underlying stock in roughly delta-equivalent quantities. The structure produces:Long stock positions paired with short options exposure. When a market maker sells call options to retail investors and institutional traders, they often buy underlying stock as a delta hedge. The stock position appears in 13F filings; the offsetting short-option exposure does not.Long stock + put options. Some structures hold long stock paired with protective puts. The stock shows up in 13F at full value; the put position offsets economic exposure.Inventory for facilitation. Market makers carry inventory to provide tight bid-ask spreads to other market participants. The inventory size scales with options-trading volume in the underlying.The 13F reports the long-stock position at full reported value. The offsetting short-options or hedge positions are not visible (Form 13F-HR captures only long equity positions, not options or short positions). Reading the long-stock figure as 'institutional ownership' is therefore misleading — it overstates the market maker's directional exposure by the full hedge offset.How to identify market-maker 13F filersFive fingerprints help spot this category:Filer name suggests market-making or proprietary trading. Susquehanna International Group, Jane Street Group, Citadel Securities (subset of Citadel Advisors), CTC LLC (Chicago Trading Company), Wolverine Trading, Optiver, Tower Research Capital, DRW Holdings, Hudson River Trading, GTS, Flow Traders, IMC, Two Sigma Securities, Virtu Financial.Position list spans high-options-volume names. Look at the top 20 of the filer's own 13F. If it contains TSLA, NVDA, MSTR, COIN, GME, AAPL, MSFT, AMZN, META in disproportionate concentrations across high-volatility names, you're looking at a market-maker book.Single-name positions cluster at high concentrations. Market-maker books typically run 5-15% concentrations in 5-10 dominant options names, very different from a discretionary stock-picker shape.Position turnover is high. Market-maker positions can shift dramatically quarter-over-quarter because options-market activity drives the hedge structure.The filer is classified `market_maker` in our database. The platform's filer-type system explicitly tags these filers to filter them out of smart-money screens.The major US market-maker 13F filersFirm13F SizeStyleSusquehanna International Group$200B+Options market making + proprietary tradingJane Street Group$100B+ETF and options market makingCitadel SecuritiesVariableUS equity and options market making (separate from Citadel Advisors fund)CTC LLC (Chicago Trading)~$50BOptions market makingWolverine Trading~$50BOptions market makingSimplex Trading~$50BOptions market makingNote: Citadel Advisors LLC (the hedge fund) is a separate entity from Citadel Securities (the market maker). Both are owned by Citadel L.P. but operate distinct mandates. Citadel Advisors runs $665+ billion across multistrategy fund books with some options-paired exposure; Citadel Securities is the pure market-making entity.How to filter market-maker inventory from holder tablesThree rules:Rule 1: Apply the filer-type filter firstIn our database, classified market makers (`filerType = market_maker`) are flagged. Filter them out when reading holder tables for active-conviction signals. Approximately 5-15% of any high-options-volume stock's holder dollar value is market-maker inventory.Rule 2: Read the active layer underneathFilter out the market-maker layer and look at the remaining holders. The active conviction signal lives below the market-maker line — at discretionary active equity managers (Capital World, Wellington, Fidelity, etc.) and value-discipline funds (Gardner Russo, Abrams Capital, etc.) running meaningful overweights versus index.Rule 3: Watch market-maker inventory changes as options-volume signalsA 20%+ change in market-maker 13F position between consecutive quarters typically reflects options-market activity rather than directional view. UnitedHealth's market-maker inventory expanded through the 2024 Change Healthcare cybersecurity crisis (more options volume = more hedge inventory) and compressed as the crisis passed.Common reading errorsThree errors retail investors make with market-maker 13F positions:Treating Susquehanna as a smart-money investor. Susquehanna's $10.34 billion UNH position is options inventory. Reading it as institutional conviction conflates options-market depth with investment view.Following the top-of-book without filer-type filtering. When the top 10 of a stock contains 4-5 market makers (as with MSTR), the actual top of active conviction lies further down the table. Susquehanna, Jane Street, CTC, Wolverine, plus options-paired Citadel together can absorb the top 10 of a high-options name.Reading market-maker accumulation as institutional buying. Susquehanna adding to its UNH position quarter-over-quarter usually reflects options-volume growth, not directional accumulation. Compare to active-manager position changes for the directional signal.Stocks most affected by market-maker inventoryHigh-options-volume names show the largest market-maker inventory concentrations:MSTR (MicroStrategy): 4 market makers in top 6 holders, combined $12.66B inventory.COIN (Coinbase): Substantial Susquehanna and Citadel positions.TSLA (Tesla): Susquehanna, Jane Street, Wolverine all hold large hedged positions.NVDA (Nvidia): Market-maker presence in top 20.GME (GameStop): Almost the entire top 10 is market-maker inventory during options-volume spikes.UNH (UnitedHealth): Susquehanna at 1.19% portfolio post-cyber-breach cycle.CRWD (CrowdStrike): Susquehanna, Jane Street, Citadel options-paired exposure.What this means for retail readersThree practical implications:For high-options-volume stocks, market-maker inventory can absorb 10-25% of total institutional holdings. Filter it out for the active-manager read.The platform's filer-type tags flag market makers automatically. Use them as a primary filter when evaluating holder tables.Single-name market-maker inventory expansion typically reflects options-volume growth or implied-volatility surface changes, not directional view.For real-time tracking of active-manager versus market-maker positioning across high-options-volume names, see the institutional signals feed. For related filer-type identification guides, see the founder-family trust decoder, Newport Trust ESOP decoder, and other resources in our explainer hub.

## FAQ

### Why does Susquehanna own $10 billion of UnitedHealth?

Susquehanna International Group is a classified market maker. Its $10.34 billion UnitedHealth position at 1.19% portfolio reflects options-driven inventory paired with short-option exposure rather than directional conviction. UNH has a deep options market — particularly after the 2024 Change Healthcare cybersecurity crisis expanded options-trading volume. Susquehanna holds large notional inventory to facilitate that market; the 13F value overstates directional exposure.

### How do market-maker 13F positions work?

US options market makers quote two-sided markets in listed options. To hedge resulting directional exposure, they buy or sell the underlying stock in roughly delta-equivalent quantities. The 13F captures only long-stock positions; the offsetting short-options or hedge positions are not visible. Reading the long-stock figure as 'institutional ownership' overstates the market maker's true directional exposure by the full hedge offset.

### How do I identify a market maker in a 13F filer list?

Five fingerprints: (1) firm name suggests market-making (Susquehanna, Jane Street, Citadel Securities, CTC, Wolverine, Optiver, Tower Research, DRW, GTS, IMC, Hudson River, Virtu); (2) position list spans high-options-volume names disproportionately; (3) single-name positions cluster at 5-15% concentrations across 5-10 dominant options stocks; (4) position turnover is high quarter-over-quarter; (5) the filer is classified market_maker in the database.

### Is Citadel Advisors a market maker?

Citadel Advisors LLC (the hedge fund managing $665+ billion across multistrategy books) is separate from Citadel Securities (the pure market-making entity). Both are owned by Citadel L.P. but operate distinct mandates. Citadel Advisors carries some options-paired exposure but also runs substantial discretionary active and quantitative strategies — its positions cannot be treated as pure market-maker inventory. Citadel Securities is the unambiguous market-making vehicle.

### Which stocks have the most market-maker inventory?

High-options-volume names show the largest market-maker inventory concentrations: MSTR (4 market makers in top 6 holders, $12.66B combined inventory), COIN, TSLA, NVDA, GME (entire top 10 is market-maker inventory during options-volume spikes), UNH, CRWD. Generally, any stock with substantial weekly options open interest and high implied volatility will have meaningful market-maker 13F positions that should be filtered out for active-conviction reads.

### Should I follow market-maker accumulation as a buy signal?

No. Market-maker accumulation typically reflects options-volume growth, implied-volatility surface changes, or hedge-structure adjustments rather than directional view. Susquehanna adding to its UNH position quarter-over-quarter usually means options trading is growing in UNH, not that Susquehanna is bullish on UNH. Compare against active-manager position changes (Wellington, Fidelity, Capital Group) for the directional signal.

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Source: 13F Insight — https://13finsight.com/learn/market-maker-13f-susquehanna-jane-street-citadel-options-inventory
Author: Sarah Mitchell — https://13finsight.com/authors/sarah-mitchell
Last updated: 2026-05-15T05:16:50.619Z