Citadel Advisors
MREO

Citadel Advisors’s Mereo BioPharma MREO Stock Holding History

Citadel Advisors’s Portfolio MREO Stock Details MREO Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2026
Q2 		$141K Buy
+444,158
New +$133K ﹤0.01% 12401
2025
Q4 		– Sell
-3,171,632
Closed -$6.04M – 13568
2025
Q3 		$6.53M Buy
3,171,632
+2,410,973
+317% +$4.44M ﹤0.01% 3893
2025
Q2 		$2.06M Buy
760,659
+417,006
+121% +$1.01M ﹤0.01% 5650
2025
Q1 		$773K Buy
343,653
+29,703
+9% +$84K ﹤0.01% 7530
2024
Q4 		$1.1M Buy
313,950
+183,692
+141% +$722K ﹤0.01% 6812
2024
Q3 		$535K Sell
130,258
-278,731
-68% -$1.15M ﹤0.01% 8117
2024
Q2 		$1.47M Buy
408,989
+365,082
+831% +$1.18M ﹤0.01% 5868
2024
Q1 		$145K Sell
43,907
-280,912
-86% -$951K ﹤0.01% 10817
2023
Q4 		$750K Sell
324,819
-1,917,606
-86% -$3.67M ﹤0.01% 7248
2023
Q3 		$2.89M Buy
2,242,425
+473,982
+27% +$629K ﹤0.01% 4544
2023
Q2 		$2.33M Sell
1,768,443
-1,279,517
-42% -$1.48M ﹤0.01% 4891
2023
Q1 		$2.15M Sell
3,047,960
-14,372
-0.5% -$12.9K ﹤0.01% 5217
2022
Q4 		$2.3M Sell
3,062,332
-13,555
-0.4% -$11.1K ﹤0.01% 5219
2022
Q3 		$2.65M Buy
3,075,887
+312,462
+11% +$382K ﹤0.01% 5059
2022
Q2 		$3.1M Sell
2,763,425
-1,142,910
-29% -$886K ﹤0.01% 4706
2022
Q1 		$4.38M Sell
3,906,335
-94,479
-2% -$122K ﹤0.01% 4439
2021
Q4 		$6.4M Sell
4,000,814
-73,806
-2% -$148K ﹤0.01% 3863
2021
Q3 		$9.86M Buy
4,074,620
+1,120,552
+38% +$2.97M ﹤0.01% 3108
2021
Q2 		$9.36M Buy
2,954,068
+516,810
+21% +$1.73M ﹤0.01% 3184
2021
Q1 		$8.21M Sell
2,437,258
-1,678,197
-41% -$5.93M ﹤0.01% 3283
2020
Q4 		$14.7M Buy
4,115,455
+4,097,346
+22,626% +$10.3M ﹤0.01% 2151
2020
Q3 		$47K Buy
+18,109
New +$52.9K ﹤0.01% 9623

Other funds holding MREO

RCMNY
Rubric Capital Management (New York) New York $10.9B AUM 70.31% 1-Year Est. Return
6CM
683 Capital Management New York $2.04B AUM 94.26% 1-Year Est. Return
Bank of America
Bank of America Charlotte, North Carolina $1.55T AUM 33.47% 1-Year Est. Return
DCM
Defilade Capital Management Emeryville, California $747M AUM
NM
Newtyn Management New York $801M AUM 23.14% 1-Year Est. Return
TC
Tejara Capital London, United Kingdom $243M AUM 9.84% 1-Year Est. Return
UBS Group
UBS Group Zurich, Switzerland $786B AUM 40.34% 1-Year Est. Return
Two Sigma Investments
Two Sigma Investments New York $138B AUM 41.87% 1-Year Est. Return
EC
EcoR1 Capital San Francisco, California $2.06B AUM 215.32% 1-Year Est. Return
Jane Street
Jane Street New York $1.21T AUM 78.12% 1-Year Est. Return

Citadel Advisors's MREO Position: Q2 2026 in Review

Citadel Advisors opened a new position in Mereo BioPharma (MREO) in Q2 2026: 444,158 shares worth $141K. The stake represents ﹤0.01% of the portfolio and ranks #12401 among its holdings. This is a return to the name: Citadel Advisors previously reported a position in MREO as recently as Q3 2025.

Citadel Advisors first reported a position in MREO in Q3 2020 and has held it in 22 quarters since. The position peaked at $14.7M in Q4 2020. 61 funds tracked by Wall St. Rank hold MREO as of Q2 2026.

  • Citadel Advisors held 444,158 shares of Mereo BioPharma worth $141K as of Q2 2026.
  • Mereo BioPharma was a new Citadel Advisors position in Q2 2026.
  • Mereo BioPharma made up ﹤0.01% of Citadel Advisors's portfolio in Q2 2026, its #12401 holding.
  • Citadel Advisors first reported a position in Mereo BioPharma in Q3 2020 and has held it in 22 quarters since.
  • Citadel Advisors's Mereo BioPharma position peaked at $14.7M in Q4 2020.
  • 61 funds tracked by Wall St. Rank held Mereo BioPharma as of Q2 2026.

Based on Citadel Advisors's 13F filing for Q2 2026, filed 14 Aug 2026.