MCRB | SERES THERAPEUTI | Owners

S&P 500$7,757.17
+0.58%
2m
DOW 30$52,856.09
+0.69%
2m
NASDAQ 100$29,822.52
+1.13%
2m
Russell 2000$276.48
+0.25%
2m
Russell 1000$422.30
+0.59%
2m
S&P 400$3,665.94
+0.40%
2m
S&P 600$1,675.64
+0.08%
2m

SERES THERAPEUTI (MCRB)

NASDAQ

$2.15-$0.15 (-6.57%)

Price as of Oct 22, 2026 7:50 PM EDT

$23.1M
Market Cap
-87.33%
1-Year Change
Biotechnology
Industry

Top Holders

Institutional

Mutual Funds

Holder	Ownership %	Shares Held	Change (Shares, %)	Report Date
FLAGSHIP VENTURES FUND IV, L.P.	141.67%	14.1M	+14.1M (+100.00%)	Mar 31, 2016
FLAGSHIP VENTURES FUND IV GENERAL PARTNER LLC	127.58%	12.7M	+12.7M (+100.00%)	Jun 30, 2016
CVI HOLDINGS, LLC	27.39%	2.7M	+2.7M (+100.00%)	Jun 30, 2022
BLACKROCK INC.	17.73%	1.8M	-5.1M (-287.33%)	Jun 30, 2024
BLACKROCK FUNDING, INC. /DE	17.73%	1.8M	0 (0.00%)	Dec 31, 2024
FLAGSHIP PIONEERING INC.	11.63%	1.2M	0 (0.00%)	Jun 30, 2026
FLAGSHIP PIONEERING, LLC	11.63%	1.2M	0 (0.00%)	Jun 30, 2026

Holder	Ownership %	Shares Held	Change (Shares, %)	Report Date
VANGUARD INDEX FUNDS	2.84%	282,019	+5,903 (+2.09%)	Jun 30, 2026
SIT MUTUAL FUNDS INC	2.48%	246,775	0 (0.00%)	Mar 28, 2024
AMERICAN CENTURY ETF TRUST	0.45%	44,839	-18,827 (-41.99%)	May 31, 2026
SCHWAB STRATEGIC TRUST	0.31%	31,077	-436 (-1.40%)	May 31, 2026
INVESCO EXCHANGE-TRADED FUND TRUST	0.13%	12,914	-1,624 (-12.58%)	Jul 31, 2026
DFA INVESTMENT DIMENSIONS GROUP INC	0.08%	7,662	0 (0.00%)	Jul 31, 2026
BRIDGEWAY FUNDS INC	0.08%	7,500	0 (0.00%)	Jun 30, 2026

Current Ownership Distribution

Institutions1.3B (67.02%)
Mutual Funds572.3M (30.21%)
Insiders52.3M (2.76%)
Other0 (0.00%)

Insider Transactions

2.76% (52.3M)
Current InsiderOwnership (%, shares)
0
Number of InsiderBuying (last 12 months)
$0.00
Amount of InsiderBuying (last 12 months)
5
Number of InsiderSelling (last 12 months)
$927,891.63
Amount of InsiderSelling (last 12 months)

Insider Name & Title	Type	Date	Transaction Value	Shares	Share Price	Shares After Transactions
DesRosier Thomas See Remarks	Sell	Aug 17, 2026	$373.10	82	$4.55	8,117
Brady Kelly See Remarks	Sell	Aug 17, 2026	$291.20	64	$4.55	8,679
DesRosier Thomas See Remarks	Exempt	Aug 15, 2026	$0.00	133	$0.00	265
Brady Kelly See Remarks	Exempt	Aug 15, 2026	$0.00	90	$0.00	179
DesRosier Thomas See Remarks	Exempt	Aug 15, 2026	$0.00	112	$0.00	667
Brady Kelly See Remarks	Exempt	Aug 15, 2026	$0.00	91	$0.00	548
DesRosier Thomas See Remarks	Exempt	Aug 15, 2026	$0.00	245	$0.00	8,199
Brady Kelly See Remarks	Exempt	Aug 15, 2026	$0.00	181	$0.00	8,743
Thorell Marella See Remarks	Award	Jul 08, 2026	$0.00	7,500	$0.00	7,500
Ausiello Dennis A	Award	Jul 08, 2026	$0.00	6,500	$0.00	6,500
Rosiello Robert L.	Award	Jul 08, 2026	$0.00	6,500	$0.00	6,500
Dere Willard H	Award	Jul 08, 2026	$0.00	6,500	$0.00	6,500
Henn Matthew R. See Remarks	Award	Jul 08, 2026	$0.00	25,000	$0.00	25,000
Fraser Claire	Award	Jul 08, 2026	$0.00	6,500	$0.00	6,500
Brady Kelly See Remarks	Award	Jul 08, 2026	$0.00	18,750	$0.00	18,750
Graves Kurt	Award	Jul 08, 2026	$0.00	6,500	$0.00	6,500
Shaff Eric D.	Award	Jul 08, 2026	$0.00	6,500	$0.00	6,500
Kender Richard N See Remarks	Award	Jul 08, 2026	$0.00	50,000	$0.00	50,000
Rosiello Robert L.	Award	Jul 01, 2026	$0.00	7,508	$0.00	7,508
Berenson Stephen	Award	Jul 01, 2026	$0.00	7,508	$0.00	7,508
Henn Matthew R. See Remarks	Award	Mar 04, 2026	$0.00	75,000	$0.00	75,000
Thorell Marella See Remarks	Award	Mar 04, 2026	$0.00	22,500	$0.00	22,500
DesRosier Thomas See Remarks	Award	Mar 04, 2026	$0.00	22,500	$0.00	22,500
Brady Kelly See Remarks	Award	Mar 04, 2026	$0.00	56,250	$0.00	56,250
Kender Richard N See Remarks	Award	Mar 04, 2026	$0.00	150,000	$0.00	150,000
Shaff Eric D.	Exempt	Feb 15, 2026	$0.00	391	$0.00	1,564
DesRosier Thomas See Remarks	Exempt	Feb 15, 2026	$0.00	133	$0.00	531
Shaff Eric D.	Exempt	Feb 15, 2026	$0.00	333	$0.00	2,656
Young Teresa L. See Remarks	Exempt	Feb 15, 2026	$0.00	133	$0.00	531
Shaff Eric D.	Exempt	Feb 15, 2026	$0.00	723	$0.00	11,836