CITADEL ADVISORS LLC MREO — MEREO BIOPHARMA GROUP PLC

Ownership history in CITADEL ADVISORS LLC  ·  57 quarters on record

AI Ownership Summary

CITADEL ADVISORS LLC reported MEREO BIOPHARMA GROUP PLC (MREO) in 57 quarterly 13F filings from 2023 Q4 through 2025 Q4. The latest visible filing shows MREO at 0.00% of the fund.

This page tracks quarterly shares, estimated market value, portfolio weight, filing dates, and disclosure-aligned stock prices directly from SEC EDGAR 13F filings. Older history is available after unlock; the visible window still shows the most recent pattern.

What this MREO ownership page tells you

This page is designed to answer the real investor question behind a 13F filing: how meaningful was CITADEL ADVISORS LLC's position in MEREO BIOPHARMA GROUP PLC, and how did that conviction change over time? You can read the holding window, peak weight, latest reported size, disclosure timing, and quarter-by-quarter changes without piecing the story together from raw SEC rows.

Freshest filing
Latest Reported Filing
2025 Q4

MREO was reported at 0.00% of portfolio in the most recent visible filing.

High-water mark
Peak Conviction
0.0% in 2025 Q3

Peak weight helps separate a token disclosure from a real conviction holding the fund genuinely cared about.

Time in book
Holding Window
2023 Q4 to 2025 Q4

Longer holding windows often tell a very different story from short-lived tactical trades or one-quarter experiments.

Decision context
Why It Matters
Position size beats headlines

Knowing that a fund owned a stock is useful. Knowing whether it was a 0.20% placeholder or a true high-conviction position is where the signal actually starts.

MREO stock page CITADEL ADVISORS LLC fund profile CITADEL ADVISORS LLC full holdings
How CITADEL ADVISORS LLC held MREO — position size vs. price
% of Fund (quarterly)    MREO price (quarter-end, indexed to 100)    SPY (indexed to 100)    QQQ (indexed to 100)
📋 Quarterly Holdings History 26 quarters  ▾
Quarter Action Sold % After 3M Timing Shares Change Chg % % of Fund Mkt Value Filed Price (Filed)
2025 Q4 ADDED — — — 617,200 +485,700 +369.4% 0.00% $257K 2026-02-14 (Est.) $0.37
2025 Q4 REDUCED 95.9% -21.4% ✅ 131,500 -3,040,132 -95.9% 0.00% $55K 2026-02-14 (Est.) $0.37
2025 Q3 ADDED — — — 3,171,632 +3,116,332 +5635.3% 0.00% $6.5M 2025-11-14 $1.78
2025 Q3 ADDED — — — 55,300 +29,600 +115.2% 0.00% $114K 2025-11-14 $1.78
2025 Q3 REDUCED 96.6% -86.4% ✅ 25,700 -734,959 -96.6% 0.00% $53K 2025-11-14 $1.78
2025 Q2 ADDED — — — 760,659 +660,859 +662.2% 0.00% $2.1M 2025-08-14 $1.71
2025 Q2 ADDED — — — 99,800 +37,600 +60.5% 0.00% $270K 2025-08-14 $1.71
2025 Q2 REDUCED 81.9% -27.7% ✅ 62,200 -281,453 -81.9% 0.00% $169K 2025-08-14 $1.71
2025 Q1 ADDED — — — 343,653 +308,953 +890.4% 0.00% $773K 2025-05-15 $2.18
2025 Q1 REDUCED 54.6% +20.4% ❌ 34,700 -41,800 -54.6% 0.00% $78K 2025-05-15 $2.18
2025 Q1 REDUCED 75.6% +20.4% ❌ 76,500 -237,450 -75.6% 0.00% $172K 2025-05-15 $2.18
2024 Q4 ADDED — — — 313,950 +216,650 +222.7% 0.00% $1.1M 2025-02-14 $2.87
2024 Q4 ADDED — — — 97,300 +13,400 +16.0% 0.00% $341K 2025-02-14 $2.87
2024 Q4 REDUCED 35.6% -35.7% ✅ 83,900 -46,358 -35.6% 0.00% $294K 2025-02-14 $2.87
2024 Q3 ADDED — — — 130,258 +16,658 +14.7% 0.00% $535K 2024-11-14 $3.82
2024 Q3 ADDED — — — 113,600 +96,900 +580.2% 0.00% $467K 2024-11-14 $3.82
2024 Q3 REDUCED 95.9% -14.4% ✅ 16,700 -392,289 -95.9% 0.00% $69K 2024-11-14 $3.82
2024 Q2 ADDED — — — 408,989 +308,689 +307.8% 0.00% $1.5M 2024-08-14 $3.95
2024 Q2 ADDED — — — 100,300 +72,400 +259.5% 0.00% $361K 2024-08-14 $3.95
2024 Q2 REDUCED 36.5% +14.2% ❌ 27,900 -16,007 -36.5% 0.00% $100K 2024-08-14 $3.95
2024 Q1 REDUCED 39.4% +10.0% ❌ 43,907 -28,593 -39.4% 0.00% $145K 2024-05-15 $3.17
2024 Q1 ADDED — — — 72,500 +39,500 +119.7% 0.00% $239K 2024-05-15 $3.17
2024 Q1 REDUCED 89.8% +10.0% ❌ 33,000 -291,819 -89.8% 0.00% $109K 2024-05-15 $3.17
2023 Q4 ADDED — — — 324,819 +309,419 +2009.2% 0.00% $750K 2024-02-14 $3.63
2023 Q4 ADDED — — — 15,400 +5,700 +58.8% 0.00% $36K 2024-02-14 $3.63
2023 Q4 REDUCED 99.6% +47.6% ❌ 9,700 -2,232,725 -99.6% 0.00% $22K 2024-02-14 $3.63
31 older quarters hidden  —  Sign in free or upgrade to Premium to see full history

🏢 Other funds also holding MREO

As of 2026 Q1 — sorted by position size

Significant Wealth Partners LLC 0.01% SmartHarvest Portfolios, LLC 0.01% Three Magnolias Financial Advisors, LLC 0.0% GAMMA Investing LLC 0.0%

FAQ About CITADEL ADVISORS LLC and MREO

These are the practical questions this page is built to answer before you even open the full history table.

How long has CITADEL ADVISORS LLC reported owning MREO?

CITADEL ADVISORS LLC reported MREO across 26 quarterly 13F filings, from 2023 Q4 through 2025 Q4.

What was the largest reported MREO position in CITADEL ADVISORS LLC's portfolio?

The largest reported portfolio weight for MREO was 0.00% in 2025 Q3.

What is the latest reported MREO position on this page?

The most recent filing on this page is 2025 Q4, when CITADEL ADVISORS LLC reported 617,200 shares, equal to 0.00% of portfolio, with an estimated market value of $257K.

What does the chart on this MREO ownership page compare?

The chart compares CITADEL ADVISORS LLC's quarterly MREO portfolio weight with the stock's indexed share price, so you can see whether the fund was building, trimming, or holding the position as price moved.

How well did CITADEL ADVISORS LLC time their MREO position?

Based on 13F filing dates vs. subsequent MREO price moves, CITADEL ADVISORS LLC correctly timed 35 out of 56 reported position changes (62%). The annualised alpha on MREO relative to SPY over the holding period was +3.3%.

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