Skip to main content Skip to main content
Institutional Ownership · SEC Form 13F

Who owns ATII (ATII)


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

Ownership as of the 2026-Q1 13F filings. 13F is disclosed up to 45 days after quarter-end, so the most recent quarter fills in over the following weeks.

54
Institutional holders
22,185,740
Shares held (tracked funds)

How the tape is positioned

8 tracked funds added or opened ATII while 10 trimmed or exited it between 2025-Q4 and 2026-Q1 — 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

ATII’s largest tracked holder by dollar value, TENOR CAPITAL MANAGEMENT Co., L.P., sizes it at 0.2% of its own reported 13F book, while the median holder sizes it at 0.1% of theirs — a 0.1pp conviction gap — its largest holder concentrates the name more heavily than the typical one.

Book-share is each fund’s reported value in ATII 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 2025-Q4 and 2026-Q1, across 54 tracked filers holding ATII, 15 increased or opened the position and 14 reduced or closed it; over the same quarter, there were no open-market insider Form 4s.

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 ATII between the 2025-Q4 and 2026-Q1 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 6

  • RLH Capital LLC$4M
  • J. Goldman & Co LP$4M
  • Quarry LP$3M
  • O'Connor Alternative Investments LLC$2M
  • Lineage Point Capital LP$1M
  • Virtu Financial LLC$561K

Full exits 3

  • Driehaus Capital Management LLC$6M
  • OCONNOR, A Distinct Business Unit of UBS ASSET MANAGEMENT AMERICAS (LLC)$2M
  • StoneX Group Inc.$524K

Largest adds

  • TORONTO DOMINION BANK$5M
  • Clear Street Group Inc.$763K

Largest trims

  • METEORA CAPITAL, LLC$4M
  • MIZUHO SECURITIES USA LLC$3M
  • WOLVERINE ASSET MANAGEMENT LLC$2M
  • GLAZER CAPITAL, LLC$1M
  • Periscope Capital Inc.$960K
  • DLD Asset Management, LP$510K

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
TENOR CAPITAL MANAGEMENT Co., L.P.1,500,000$16M6.5%2026-Q1
Magnetar Financial LLC1,300,000$14M5.6%2026-Q1
D. E. Shaw & Co., Inc.1,138,500$12M5.0%2026-Q1
Linden Advisors LP1,000,000$10M4.3%2026-Q1
AQR Arbitrage LLC trimmed920,672$10M4.0%2026-Q1
Westchester Capital Management, LLC907,144$9M3.9%2026-Q1
LMR Partners LLP850,000$9M3.7%2026-Q1
Ghisallo Capital Management LLC800,000$8M3.5%2026-Q1
Governors Lane LP added759,556$8M3.3%2026-Q1
Alberta Investment Management Corp750,000$8M3.3%2026-Q1
GLAZER CAPITAL, LLC trimmed750,000$8M3.2%2026-Q1
TWO SIGMA INVESTMENTS, LP725,000$8M3.1%2026-Q1
Hudson Bay Capital Management LP700,000$7M3.0%2026-Q1
Radcliffe Capital Management, L.P. added661,337$7M2.9%2026-Q1
TORONTO DOMINION BANK added650,000$7M2.8%2026-Q1
Sculptor Capital LP600,646$6M2.6%2026-Q1
Jain Global LLC500,000$5M2.2%2026-Q1
PICTON MAHONEY ASSET MANAGEMENT500,000$5M2.2%2026-Q1
MOORE CAPITAL MANAGEMENT, LP450,000$5M1.9%2026-Q1
RIVERNORTH CAPITAL MANAGEMENT, LLC trimmed427,500$4M1.9%2026-Q1
RLH Capital LLC new400,907$4M1.7%2026-Q1
COMMONWEALTH OF PENNSYLVANIA PUBLIC SCHOOL EMPLS RETRMT SYS400,000$4M1.7%2026-Q1
J. Goldman & Co LP new369,778$4M1.6%2026-Q1
Periscope Capital Inc. trimmed352,880$4M1.5%2026-Q1
GOLDMAN SACHS GROUP INC added327,450$3M1.4%2026-Q1
MILLENNIUM MANAGEMENT LLC307,985$3M1.3%2026-Q1
Mint Tower Capital Management B.V.300,000$3M1.3%2026-Q1
METEORA CAPITAL, LLC trimmed295,612$3M1.3%2026-Q1
Centiva Capital, LP285,515$3M1.2%2026-Q1
Quarry LP new285,000$3M1.2%2026-Q1
Shaolin Capital Management LLC270,783$3M1.2%2026-Q1
ARISTEIA CAPITAL, L.L.C.250,000$3M1.1%2026-Q1
WHITEBOX ADVISORS LLC250,000$3M1.1%2026-Q1
Verition Fund Management LLC231,470$2M1.0%2026-Q1
BERKLEY W R CORP trimmed208,065$2M0.9%2026-Q1
O'Connor Alternative Investments LLC new200,000$2M0.9%2026-Q1
L1 Global Manager Pty Ltd200,000$2M0.9%2026-Q1
Schonfeld Strategic Advisors LLC173,515$2M0.8%2026-Q1
DLD Asset Management, LP trimmed150,000$2M0.6%2026-Q1
READYSTATE ASSET MANAGEMENT LP added148,734$2M0.6%2026-Q1
WOLVERINE ASSET MANAGEMENT LLC trimmed134,280$1M0.6%2026-Q1
MMCAP International Inc. SPC125,000$1M0.5%2026-Q1
GRITSTONE ASSET MANAGEMENT LLC99,081$1M0.4%2026-Q1
Lineage Point Capital LP new95,895$1M0.4%2026-Q1
K2 PRINCIPAL FUND, L.P.87,900$915K0.4%2026-Q1
Baird Financial Group, Inc.78,500$819K0.3%2026-Q1
Clear Street Group Inc. added77,452$806K0.3%2026-Q1
CSS LLC/IL57,143$595K0.2%2026-Q1
Virtu Financial LLC new53,686$561K0.2%2026-Q1
BNP PARIBAS FINANCIAL MARKETS new37,744$393K0.2%2026-Q1
MIZUHO SECURITIES USA LLC trimmed19,469$202K0.1%2026-Q1
GEODE CAPITAL MANAGEMENT, LLC new11,102$116K0.0%2026-Q1
CITADEL ADVISORS LLC new10,377$108K0.0%2026-Q1
MORGAN STANLEY trimmed62$6450.0%2026-Q1
Driehaus Capital Management LLC573,083$6M2.5%2025-Q4 stale
OCONNOR, A Distinct Business Unit of UBS ASSET MANAGEMENT AMERICAS (LLC) new200,000$2M0.9%2025-Q4 stale
StoneX Group Inc. new50,613$524K0.2%2025-Q4 stale
CLEAR STREET LLC new37,534$384K0.2%2025-Q2 stale
Warberg Asset Management LLC10,000$104K0.0%2025-Q4 stale
CONCOURSE FINANCIAL GROUP SECURITIES, INC. new00.0%2025-Q2 stale

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