Skip to main content
Institutional Ownership · SEC Form 13F

Who owns X4 Pharmaceuticals (XFOR)


Which tracked institutional funds hold XFOR, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See XFOR company fundamentals →

Ownership as of the 2026-Q2 13F filings (latest filed 2026-09-22). 13F is disclosed up to 45 days after quarter-end, so the most recent quarter fills in over the following weeks.

88
Institutional holders
99M
Shares held (tracked funds)

How the tape is positioned

28 tracked funds added or opened XFOR while 13 trimmed or exited it between 2026-Q1 and 2026-Q2 — the tape is split. When large holders disagree on a name, the funds moving first are sometimes ahead of the story.

A prompt to read the filings, not a verdict. 13F is a quarter-end snapshot disclosed up to 45 days late; a fund adds or exits for mandate, benchmark, and timing reasons that have nothing to do with a view on the stock. This is a starting question, not a signal to trade.

Conviction spread

XFOR’s largest tracked holder by dollar value, MORGAN STANLEY, sizes it at 0.0% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 0.0pp conviction gap — its largest holder concentrates the name more heavily than the typical one.

Book-share is each fund’s reported value in XFOR divided by its whole reported 13F book, so it is comparable across funds of different sizes and is unaffected by stock splits. A higher share means a fund has committed more of its book to the name — a starting question about conviction, not a verdict or a signal to trade.

Institutional & insider positioning

Between 2026-Q1 and 2026-Q2, across 88 tracked filers holding XFOR, 55 increased or opened the position and 39 reduced or closed it; over the same quarter, open-market insider Form 4s were net sales.

This fuses two public signals for the same quarter — how tracked institutions changed their positions and whether insiders bought or sold in the open market. It describes what was filed; it is a starting question, not a verdict or a signal to trade.

New buyers & exits

Funds opening or closing a position in XFOR between the 2026-Q1 and 2026-Q2 13F filings, and the largest changes among funds holding it in both. New buyers and exits are counted on fund presence (split-invariant); adds and trims are measured on reported value.

New buyers 4

  • VANGUARD PORTFOLIO MANAGEMENT LLC$3M
  • Verdad Advisers, LP$2M
  • Bank of New York Mellon Corp$917K
  • Nuveen, LLC$502K

Full exits 7

  • MILLENNIUM MANAGEMENT LLC$5M
  • STEMPOINT CAPITAL LP$4M
  • MARSHALL WACE, LLP$1M
  • ACORN CAPITAL ADVISORS, LLC$967K
  • Qube Research & Technologies Ltd$904K
  • Pale Fire Capital SE$692K

Largest adds

  • BlackRock, Inc.$21M
  • PERCEPTIVE ADVISORS LLC$9M
  • Venrock Adviser, LLC$8M
  • GEODE CAPITAL MANAGEMENT, LLC$6M
  • Saturn V Capital Management LP$6M
  • FMR LLC$5M

Largest trims

  • Empery Asset Management, LP$5M
  • SUSQUEHANNA INTERNATIONAL GROUP, LLP$3M
  • SAMSARA BIOCAPITAL, LLC$1M
  • UBS Group AG$833K
  • BANK OF AMERICA CORP /DE/$403K
  • Stonepine Capital Management, LLC$334K

Institutional holders

One row per tracked fund, largest reported value first. “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding. Rows marked stale are from an earlier filing than the security’s latest quarter — that fund is absent from the newest snapshot (position exited, or reported under a different name).

FundSharesReported value% of valueQuarter
MORGAN STANLEY trimmed9,461,279$44M8.8%2026-Q2
FMR LLC added8,321,657$39M7.8%2026-Q2
Bain Capital Life Sciences Investors, LLC7,967,454$37M7.4%2026-Q2
PERCEPTIVE ADVISORS LLC added7,933,491$37M7.4%2026-Q2
Saturn V Capital Management LP added6,973,343$33M6.5%2026-Q2
Empery Asset Management, LP trimmed6,930,591$32M6.5%2026-Q2
Deep Track Capital, LP trimmed5,878,757$27M5.5%2026-Q2
BlackRock, Inc. added5,554,906$26M5.2%2026-Q2
Kalehua Capital Management LLC3,722,840$17M3.5%2026-Q2
VANGUARD CAPITAL MANAGEMENT LLC added3,715,859$17M3.5%2026-Q2
NEA Management Company, LLC3,233,743$15M3.0%2026-Q2
Rosalind Advisors, Inc.3,214,766$15M3.0%2026-Q2
BRAIDWELL LP trimmed2,922,754$14M2.7%2026-Q2
Blackstone Inc.2,681,922$13M2.5%2026-Q2
Trails Edge Capital Partners, LP2,571,478$12M2.4%2026-Q2
Nantahala Capital Management, LLC2,449,468$11M2.3%2026-Q2
BVF INC/IL2,233,742$10M2.1%2026-Q2
GEODE CAPITAL MANAGEMENT, LLC added2,098,047$10M2.0%2026-Q2
Venrock Adviser, LLC added1,934,253$9M1.8%2026-Q2
SAMSARA BIOCAPITAL, LLC trimmed1,395,587$7M1.3%2026-Q2
STATE STREET CORP added1,296,017$6M1.2%2026-Q2
Woodline Partners LP1,001,095$5M0.9%2026-Q2
GOLDMAN SACHS GROUP INC added916,536$4M0.9%2026-Q2
NORTHERN TRUST CORP added652,849$3M0.6%2026-Q2
VANGUARD FIDUCIARY TRUST CO added572,038$3M0.5%2026-Q2
VANGUARD PORTFOLIO MANAGEMENT LLC new542,128$3M0.5%2026-Q2
Verdad Advisers, LP new352,093$2M0.3%2026-Q2
CHARLES SCHWAB INVESTMENT MANAGEMENT INC added263,264$1M0.2%2026-Q2
Stonepine Capital Management, LLC trimmed224,989$1M0.2%2026-Q2
Bank of New York Mellon Corp trimmed196,340$917K0.2%2026-Q2
Affinity Asset Advisors, LLC145,000$677K0.1%2026-Q2
Nuveen, LLC new107,389$502K0.1%2026-Q2
Invesco Ltd. added96,772$452K0.1%2026-Q2
ALPS ADVISORS INC new95,726$447K0.1%2026-Q2
RHUMBLINE ADVISERS trimmed95,081$444K0.1%2026-Q2
Susquehanna Portfolio Strategies, LLC trimmed87,282$408K0.1%2026-Q2
DEUTSCHE BANK AG\ trimmed78,885$368K0.1%2026-Q2
AMERICAN CENTURY COMPANIES INC new74,795$349K0.1%2026-Q2
CITIGROUP INC added70,112$327K0.1%2026-Q2
WELLS FARGO & COMPANY/MN added67,712$316K0.1%2026-Q2
Palumbo Wealth Management LLC trimmed67,116$313K0.1%2026-Q2
Squarepoint Ops LLC added67,078$313K0.1%2026-Q2
PRICE T ROWE ASSOCIATES INC /MD/ trimmed66,379$310K0.1%2026-Q2
UBS Group AG trimmed58,043$271K0.1%2026-Q2
WELLINGTON MANAGEMENT GROUP LLP new51,800$242K0.0%2026-Q2
MetLife Investment Management, LLC new47,969$224K0.0%2026-Q2
BANK OF AMERICA CORP /DE/ trimmed46,861$219K0.0%2026-Q2
Point72 Asset Management, L.P. trimmed41,072$192K0.0%2026-Q2
MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. trimmed37,073$173K0.0%2026-Q2
Jump Financial, LLC added34,253$160K0.0%2026-Q2
Vanguard Global Advisers, LLC32,977$154K0.0%2026-Q2
JPMORGAN CHASE & CO added33,552$142K0.0%2026-Q2
Police & Firemen's Retirement System of New Jersey trimmed23,846$111K0.0%2026-Q2
AXQ CAPITAL, LP new22,880$107K0.0%2026-Q2
MANUFACTURERS LIFE INSURANCE COMPANY, THE new22,083$103K0.0%2026-Q2
BARCLAYS PLC added19,439$91K0.0%2026-Q2
TWO SIGMA INVESTMENTS, LP added19,426$91K0.0%2026-Q2
STIFEL FINANCIAL CORP trimmed18,519$86K0.0%2026-Q2
RENAISSANCE TECHNOLOGIES LLC trimmed18,100$85K0.0%2026-Q2
INTECH INVESTMENT MANAGEMENT LLC trimmed17,290$81K0.0%2026-Q2
NEW YORK STATE COMMON RETIREMENT FUND trimmed16,500$77K0.0%2026-Q2
BNP PARIBAS FINANCIAL MARKETS added16,384$77K0.0%2026-Q2
VOYA INVESTMENT MANAGEMENT LLC trimmed15,838$74K0.0%2026-Q2
CAXTON CORP15,557$73K0.0%2026-Q2
WINTON GROUP Ltd added14,400$67K0.0%2026-Q2
SUSQUEHANNA INTERNATIONAL GROUP, LLP trimmed14,050$66K0.0%2026-Q2
Creative Planning added13,872$65K0.0%2026-Q2
ALLIANCEBERNSTEIN L.P. trimmed14,580$60K0.0%2026-Q2
PRUDENTIAL FINANCIAL INC new12,500$58K0.0%2026-Q2
ProShare Advisors LLC trimmed10,588$49K0.0%2026-Q2
Indivisible Partners10,000$47K0.0%2026-Q2
Pettinga Financial Advisors LLC new10,000$47K0.0%2026-Q2
Legal & General Group Plc trimmed7,858$37K0.0%2026-Q2
Tower Research Capital LLC (TRC) added7,745$36K0.0%2026-Q2
Ameritas Investment Partners, Inc. trimmed7,338$34K0.0%2026-Q2
Russell Investments Group, Ltd. added7,178$34K0.0%2026-Q2
ROYAL BANK OF CANADA added2,559$12K0.0%2026-Q2
PNC Financial Services Group, Inc.1,759$8K0.0%2026-Q2
Sterling Capital Management LLC added1,629$8K0.0%2026-Q2
CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM trimmed1,113$5K0.0%2026-Q2
GROUP ONE TRADING LLC712$3K0.0%2026-Q2
Bleichroeder LP595$3K0.0%2026-Q2
Blue Trust, Inc.284$1K0.0%2026-Q2
Rockefeller Capital Management L.P.33$1540.0%2026-Q2
JONES FINANCIAL COMPANIES LLLP38$1530.0%2026-Q2
Caitong International Asset Management Co., Ltd new30$1400.0%2026-Q2
SBI Securities Co., Ltd. trimmed9$420.0%2026-Q2
HighMark Wealth Management LLC6$280.0%2026-Q2
MILLENNIUM MANAGEMENT LLC added1,210,514$5M1.0%2026-Q1 stale (1 quarter behind)
STEMPOINT CAPITAL LP trimmed850,742$4M0.7%2026-Q1 stale (1 quarter behind)
MARSHALL WACE, LLP added336,834$1M0.3%2026-Q1 stale (1 quarter behind)
ACORN CAPITAL ADVISORS, LLC trimmed234,039$967K0.2%2026-Q1 stale (1 quarter behind)
Qube Research & Technologies Ltd added218,954$904K0.2%2026-Q1 stale (1 quarter behind)
Pale Fire Capital SE167,590$692K0.1%2026-Q1 stale (1 quarter behind)
Brevan Howard Capital Management LP new127,321$526K0.1%2026-Q1 stale (1 quarter behind)
VANGUARD GROUP INC added3,423,662$14M2.7%2025-Q4 stale (2 quarters behind)
Siren, L.L.C. new1,500,000$6M1.2%2025-Q4 stale (2 quarters behind)
SILVERARC CAPITAL MANAGEMENT, LLC new357,387$1M0.3%2025-Q4 stale (2 quarters behind)
KINGDON CAPITAL MANAGEMENT, L.L.C. added933,332$3M0.6%2025-Q3 stale (3 quarters behind)
BOOTHBAY FUND MANAGEMENT, LLC new343,963$1M0.2%2025-Q3 stale (3 quarters behind)

Ownership over time

Tracked institutional holder count and total shares held by filing quarter (independent scales). The curated-era tail and any mid-ingest latest quarter are handled honestly — a partial quarter is not drawn as a collapse.

HoldersTotal shares

Reading this table

Funds hold the same stock for different reasons — an index fund “holds” almost everything, an active manager sizes a name to a mandate and a benchmark, and each fund entered at its own price and time. Because 13F is filed up to 45 days after quarter-end, every row is a backward-looking snapshot; a manager may have traded since. Share-class siblings (a company’s A and C shares) are rolled up to one line so a dual-class name is never double-counted. Compare like-for-like. A large holder is not an endorsement, and a fund exiting is not a warning — this is a starting question, not a verdict.

About 13F filings

A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It covers long US-listed equities only — not short positions, options, cash, or private holdings — and the funds shown are the large sample we track, not the complete 13F universe.

Learn how to read institutional ownership