Vault-13

HARVARD BIOSCIENCE INC HBIO

COM · Common Stock · CUSIP 416906204

Company in Holliston, United States

35 institutional holders +1 vs Q1 2026
1,353,4151.4m shares reported held*
29.7% of all shares outstanding*
$8.3mreported value*
4 new 3 added 16 reduced 2 sold out net bought ≈ $23.5k (+3.8k shares)

* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once. Holder counts are more reliable. Shares outstanding: 4.6m as of 2026-08-04, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $6.15. Options: 1 managers hold calls ($14.1k notional), 0 hold puts (—).

Trends to Q2 2026

Institutional holders

Managers reporting a position, each quarter

02040Q3 24: 1Q4 24: 1Q1 25: 1Q2 25: 2Q3 25: 1Q4 25: 1Q1 26: 34Q2 26: 3535Q3 24Q1 25Q3 25Q1 26Q2 26
Numbers
QuarterHolders
Q3 20241
Q4 20241
Q1 20251
Q2 20252
Q3 20251
Q4 20251
Q1 202634
Q2 202635

Buyers vs sellers

Managers adding to or starting a position, vs cutting or selling out

Bought or addedCut or sold out
40040Q4 24: 1 bought or addedQ4 24: 0 cut or sold outQ4 24Q1 25: 0 bought or addedQ1 25: 0 cut or sold outQ2 25: 0 bought or addedQ2 25: 0 cut or sold outQ2 25Q3 25: 0 bought or addedQ3 25: 2 cut or sold outQ4 25: 0 bought or addedQ4 25: 0 cut or sold outQ4 25Q1 26: 30 bought or addedQ1 26: 1 cut or sold outQ2 26: 7 bought or addedQ2 26: 18 cut or sold outQ2 26
Numbers
QuarterBought or addedCut or sold out
Q4 202410
Q1 202500
Q2 202500
Q3 202502
Q4 202500
Q1 2026301
Q2 2026718

Calls vs puts

Options held, notional value, last 4 quarters. P/C = puts ÷ calls

CallsPuts
$0$50k$100k$150kQ3 25 calls: $0Q3 25 puts: $0Q3 25P/C —Q4 25 calls: $0Q4 25 puts: $0Q4 25P/C —Q1 26 calls: $112.5kQ1 26 puts: $10.7kQ1 26P/C 0.10Q2 26 calls: $14.1kQ2 26 puts: $0Q2 26P/C 0.00
Numbers
QuarterCallsPutsP/C
Q3 2025$0$0—
Q4 2025$0$0—
Q1 2026$112.5k$10.7k0.10
Q2 2026$14.1k$00.00

Biggest buyers

Mink Brook Asset Management LLC New +33,369+33.4k
CITADEL ADVISORS LLC New +13,251+13.3k
GOLDMAN SACHS GROUP INC New +10,657+10.7k
UBS Group AG Added +9,176+9.2k
VANGUARD CAPITAL MANAGEMENT LLC Added +6,312+6.3k
TWO SIGMA INVESTMENTS, LP Added +428+428
BARCLAYS PLC New +26+26

Biggest sellers

MILLENNIUM MANAGEMENT LLC Reduced -13,712-13.7k
GEODE CAPITAL MANAGEMENT, LLC Reduced -11,956-12.0k
JANE STREET GROUP, LLC Reduced -9,848-9.8k
WEBER CAPITAL MANAGEMENT LLC /ADV Reduced -9,176-9.2k
CITIGROUP INC Sold out -6,273-6.3k
Williams & Novak, LLC Reduced -6,103-6.1k
JPMORGAN CHASE & CO Reduced -4,268-4.3k
RENAISSANCE TECHNOLOGIES LLC Reduced -2,100-2.1k
CORSAIR CAPITAL MANAGEMENT, L.P. Reduced -2,000-2.0k
GROUP ONE TRADING LLC Reduced -1,942-1.9k

Biggest calls

GROUP ONE TRADING LLC Reduced $14.1k2.3k shares

Biggest puts

None

Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.

Major shareholders (over 5%)

Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.

HolderStakeChangeShares Last filed
Snider William 13D · may seek influence new · filed 2026-03-23
Stated purposeThe information contained above in Item 1 and Item 3 of this Schedule 13D is incorporated herein by reference. The Reporting Persons acquired the securities of the Issuer in connection with the Loan Agreement. Mr. Snider serves a member of the board of directors of the Issuer and, in such capacity, may have influence over the corporate activities of the Issuer, including activities which may relate to items described in subparagraphs (a) through (j) of Item 4 of Schedule 13D. Mr. Snider is a partner of BroadOak Capital Partners and manager of BroadOak Income Fund and BroadOak Fund VI. Subject to the Issuer's Insider Trading Policy and other applicable policies, Mr. Snider may from time to time buy or sell securities of the Issuer as appropriate for his personal circumstances, and may rece… Full filing
16.0% new 846.0k≈ $4.9m 2026-03-23

Insider purchases and sales since 1 Apr 2026

Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.

Officers and directors buying vs selling

Number of people, by quarter (10% owners not included)

BuyingSelling
404Q4 24: 0 buyingQ4 24: 0 sellingQ1 25: 0 buyingQ1 25: 0 sellingQ1 25Q2 25: 0 buyingQ2 25: 0 sellingQ3 25: 0 buyingQ3 25: 0 sellingQ3 25Q4 25: 0 buyingQ4 25: 0 sellingQ1 26: 4 buyingQ1 26: 0 sellingQ1 26Q2 26: 0 buyingQ2 26: 0 sellingQ3 26: 0 buyingQ3 26: 0 sellingQ3 26
Numbers
QuarterBuyingBoughtSellingSoldSold under a plan
Q4 20240—0——
Q1 20250—0——
Q2 20250—0——
Q3 20250—0——
Q4 20250—0——
Q1 20264$202.4k0——
Q2 20260—0——
Q3 20260—0——

None reported since 1 Apr 2026.

Holders, Q2 2026

#ManagerLocationShares Value% of their portfolioChangeShares change
1 WEBER CAPITAL MANAGEMENT LLC /ADV 1.63% of their portfolio Dover, MA 310,861310.9k $1.9m $1.9m 1.63% Reduced -9.2k -9,176
2 ACADIAN ASSET MANAGEMENT LLC 0.00% of their portfolio Boston, MA 179,614179.6k $1.1m $1.1m 0.00% Unchanged
3 VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio MALVERN, PA 169,625169.6k $1.0m $1.0m 0.00% Added +6.3k +6,312
4 CORSAIR CAPITAL MANAGEMENT, L.P. 0.10% of their portfolio NEW YORK, NY 122,810122.8k $755.3k $755.3k 0.10% Reduced -2.0k -2,000
5 TWO SIGMA INVESTMENTS, LP 0.00% of their portfolio NEW YORK, NY 114,545114.5k $704.5k $704.5k 0.00% Added +428 +428
6 RENAISSANCE TECHNOLOGIES LLC 0.00% of their portfolio NEW YORK, NY 99,32799.3k $610.9k $610.9k 0.00% Reduced -2.1k -2,100
7 BlackRock, Inc. 0.00% of their portfolio New York, NY 61,83461.8k $380.3k $380.3k 0.00% Reduced -392 -392
8 GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio BOSTON, MA 47,55547.6k $292.5k $292.5k 0.00% Reduced -12.0k -11,956
9 Mink Brook Asset Management LLC 0.09% of their portfolio West Palm Beach, FL 33,36933.4k $205.2k $205.2k 0.09% New
10 MILLENNIUM MANAGEMENT LLC 0.00% of their portfolio NEW YORK, NY 32,62032.6k $200.6k $200.6k 0.00% Reduced -13.7k -13,712
11 VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio MALVERN, PA 27,73027.7k $170.5k $170.5k 0.00% Unchanged
12 ESSEX INVESTMENT MANAGEMENT CO LLC 0.02% of their portfolio BOSTON, MA 26,97327.0k $165.9k $165.9k 0.02% Reduced -48 -48
13 Williams & Novak, LLC 0.09% of their portfolio WESTLAKE VILLAGE, CA 20,94920.9k $128.8k $128.8k 0.09% Reduced -6.1k -6,103
14 UBS Group AG 0.00% of their portfolio ZURICH, V8 17,58117.6k $108.1k $108.1k 0.00% Added +9.2k +9,176
15 RBF Capital, LLC 0.00% of their portfolio RENO, NV 16,00016.0k $98.4k $98.4k 0.00% Unchanged
16 STATE STREET CORP 0.00% of their portfolio BOSTON, MA 14,93214.9k $91.8k $91.8k 0.00% Unchanged
17 JANE STREET GROUP, LLC 0.00% of their portfolio NEW YORK, NY 13,98214.0k $86.0k $86.0k 0.00% Reduced -9.8k -9,848
18 CITADEL ADVISORS LLC 0.00% of their portfolio MIAMI, FL 13,25113.3k $81.5k $81.5k 0.00% New
19 GOLDMAN SACHS GROUP INC 0.00% of their portfolio NEW YORK, NY 10,65710.7k $65.5k $65.5k 0.00% New
20 Bank of New York Mellon Corp 0.00% of their portfolio NEW YORK, NY 10,23010.2k $62.9k $62.9k 0.00% Unchanged
21 FMR LLC 0.00% of their portfolio BOSTON, MA 3,1793.2k $19.6k $19.6k 0.00% Reduced -95 -95
22 MORGAN STANLEY 0.00% of their portfolio NEW YORK, NY 1,6271.6k $10.0k $10.0k 0.00% Reduced -1 -1
23 Vanguard Global Advisers, LLC 0.00% of their portfolio MALVERN, PA 1,2211.2k $7.5k $7.5k 0.00% Unchanged
24 SBI Securities Co., Ltd. 0.00% of their portfolio TOKYO, M0 866866 $5.3k $5.3k 0.00% Unchanged
25 Tower Research Capital LLC (TRC) 0.00% of their portfolio NEW YORK, NY 580580 $3.6k $3.6k 0.00% Reduced -572 -572
26 Brown Shipley& Co Ltd 0.00% of their portfolio LONDON, X0 478478 $2.9k $2.9k 0.00% Unchanged
27 GROUP ONE TRADING LLC 0.00% of their portfolio CHICAGO, IL 240240 $1.5k $1.5k 0.00% Reduced -1.9k -1,942
28 NISA INVESTMENT ADVISORS, LLC 0.00% of their portfolio ST. LOUIS, MO 228228 $1.4k $1.4k 0.00% Unchanged
29 PENSION & WEALTH MANAGEMENT ADVISORS, INC. 0.00% of their portfolio WALTHAM, MA 225225 $1.4k $1.4k 0.00% Unchanged
30 JPMORGAN CHASE & CO 0.00% of their portfolio NEW YORK, NY 195195 $1.2k $1.2k 0.00% Reduced -4.3k -4,268
31 BNP PARIBAS FINANCIAL MARKETS 0.00% of their portfolio PARIS, I0 6666 $406 $406 0.00% Reduced -2 -2
32 BARCLAYS PLC 0.00% of their portfolio LONDON, X0 2626 $160 $160 0.00% New
33 ROYAL BANK OF CANADA 0.00% of their portfolio TORONTO, A6 1515 $0 $0 0.00% Reduced -840 -840
34 PNC Financial Services Group, Inc. 0.00% of their portfolio Pittsburgh, PA 1414 $86 $86 0.00% Unchanged
35 SHP Wealth Management 0.00% of their portfolio PLYMOUTH, MA 1010 $62 $62 0.00% Unchanged