Vault-13

FUEL TECH INC FTEK

COM · Common Stock · CUSIP 359523107

45 institutional holders -3 vs Q3 2025
7,566,5827.6m shares reported held*
24.3% of all shares outstanding*
$11.8mreported value*
10 new 12 added 8 reduced 12 sold out net bought ≈ $451.4k (+289.4k 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: 31.1m as of 2025-10-31, 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 ≈ $1.56. Options: 3 managers hold calls ($141.3k notional), 2 hold puts ($37.1k).

Trends to Q4 2025

Institutional holders

Managers reporting a position, each quarter

0204060Q3 22: 37Q4 22: 42Q1 23: 38Q2 23: 41Q3 23: 39Q4 23: 37Q1 24: 34Q2 24: 35Q3 24: 37Q4 24: 40Q1 25: 36Q2 25: 37Q3 25: 48Q4 25: 4545Q3 22Q2 23Q1 24Q4 24Q4 25
Numbers
QuarterHolders
Q3 202237
Q4 202242
Q1 202338
Q2 202341
Q3 202339
Q4 202337
Q1 202434
Q2 202435
Q3 202437
Q4 202440
Q1 202536
Q2 202537
Q3 202548
Q4 202545

Buyers vs sellers

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

Bought or addedCut or sold out
40040Q1 24: 10 bought or addedQ1 24: 13 cut or sold outQ2 24: 12 bought or addedQ2 24: 10 cut or sold outQ2 24Q3 24: 16 bought or addedQ3 24: 7 cut or sold outQ4 24: 16 bought or addedQ4 24: 9 cut or sold outQ4 24Q1 25: 15 bought or addedQ1 25: 16 cut or sold outQ2 25: 15 bought or addedQ2 25: 16 cut or sold outQ2 25Q3 25: 27 bought or addedQ3 25: 13 cut or sold outQ4 25: 22 bought or addedQ4 25: 20 cut or sold outQ4 25
Numbers
QuarterBought or addedCut or sold out
Q1 20241013
Q2 20241210
Q3 2024167
Q4 2024169
Q1 20251516
Q2 20251516
Q3 20252713
Q4 20252220

Calls vs puts

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

CallsPuts
$0$250k$500k$750k$1mQ1 25 calls: $46.8kQ1 25 puts: $11.6kQ1 25P/C 0.25Q2 25 calls: $35.8kQ2 25 puts: $310.5kQ2 25P/C 8.68Q3 25 calls: $930.2kQ3 25 puts: $59.0kQ3 25P/C 0.06Q4 25 calls: $141.3kQ4 25 puts: $37.1kQ4 25P/C 0.26
Numbers
QuarterCallsPutsP/C
Q1 2025$46.8k$11.6k0.25
Q2 2025$35.8k$310.5k8.68
Q3 2025$930.2k$59.0k0.06
Q4 2025$141.3k$37.1k0.26

Biggest buyers

CITADEL ADVISORS LLC Added +376,994+377.0k
RENAISSANCE TECHNOLOGIES LLC Added +249,089+249.1k
TWO SIGMA INVESTMENTS, LP New +126,160+126.2k
XTX Topco Ltd Added +122,291+122.3k
VANGUARD GROUP INC Added +112,139+112.1k
MARSHALL WACE, LLP New +81,011+81.0k
TWO SIGMA ADVISERS, LP New +67,500+67.5k
SUSQUEHANNA INTERNATIONAL GROUP, LLP Added +27,990+28.0k
JANE STREET GROUP, LLC Added +23,860+23.9k
Virtu Financial LLC New +17,254+17.3k

Biggest sellers

Informed Momentum Co LLC Sold out -338,712-338.7k
Mercuria Capital Strategies, LLC Sold out -240,000-240.0k
Murchinson Ltd. Sold out -150,000-150.0k
BOOTHBAY FUND MANAGEMENT, LLC Sold out -41,251-41.3k
SIMPLEX TRADING, LLC Reduced -39,202-39.2k
Integrated Wealth Concepts LLC Sold out -35,000-35.0k
GOLDMAN SACHS GROUP INC Sold out -31,300-31.3k
HRT FINANCIAL LP Sold out -23,329-23.3k
Advisory Services Network, LLC Sold out -21,627-21.6k
NewEdge Advisors, LLC Reduced -15,326-15.3k

Biggest calls

JANE STREET GROUP, LLC New $72.7k46.6k shares
CITADEL ADVISORS LLC Reduced $49.6k31.8k shares
SIMPLEX TRADING, LLC Reduced $19.0k12.2k shares

Biggest puts

SUSQUEHANNA INTERNATIONAL GROUP, LLP New $33.2k21.3k shares
SIMPLEX TRADING, LLC Unchanged $3.9k2.5k shares

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.

No one currently above 5% in the filings since 19 Dec 2024.

Fell to 5% or below in the last year: GRACE & WHITE INC /NY (4.9%, 2026-10-07)

Insider purchases and sales in Q4 2025

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
404Q1 24: 0 buyingQ1 24: 0 sellingQ2 24: 0 buyingQ2 24: 0 sellingQ2 24Q3 24: 3 buyingQ3 24: 0 sellingQ4 24: 1 buyingQ4 24: 0 sellingQ4 24Q1 25: 1 buyingQ1 25: 0 sellingQ2 25: 0 buyingQ2 25: 1 sellingQ2 25Q3 25: 0 buyingQ3 25: 0 sellingQ4 25: 0 buyingQ4 25: 0 sellingQ4 25
Numbers
QuarterBuyingBoughtSellingSoldSold under a plan
Q1 20240—0——
Q2 20240—0——
Q3 20243$50.0k0——
Q4 20241$50.1k0——
Q1 20251$15.8k0——
Q2 20250—1$21.1k—
Q3 20250—0——
Q4 20250—0——

None reported in Q4 2025.

Holders, Q4 2025

#ManagerLocationShares Value% of their portfolioChangeShares change
1 GRACE & WHITE INC /NY 0.41% of their portfolio NY, NY 1,485,8831.5m $2.3m $2.3m 0.41% Reduced -5.8k -5,800
2 RENAISSANCE TECHNOLOGIES LLC 0.00% of their portfolio NEW YORK, NY 1,147,9951.1m $1.8m $1.8m 0.00% Added +249.1k +249,089
3 VANGUARD GROUP INC 0.00% of their portfolio Valley Forge, PA 1,126,0031.1m $1.8m $1.8m 0.00% Added +112.1k +112,139
4 GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio BOSTON, MA 518,939518.9k $809.6k $809.6k 0.00% Reduced -4.9k -4,879
5 CITADEL ADVISORS LLC 0.00% of their portfolio MIAMI, FL 504,017504.0k $786.3k $786.3k 0.00% Added +377.0k +376,994
6 BlackRock, Inc. 0.00% of their portfolio New York, NY 410,364410.4k $640.2k $640.2k 0.00% Unchanged
7 Peapod Lane Capital LLC 0.48% of their portfolio Bedford Hills, NY 359,643359.6k $561.0k $561.0k 0.48% Added +2.7k +2,705
8 US BANCORP \DE\ 0.00% of their portfolio MINNEAPOLIS, MN 304,776304.8k $475.5k $475.5k 0.00% Unchanged
9 JANE STREET GROUP, LLC 0.00% of their portfolio NEW YORK, NY 260,782260.8k $406.8k $406.8k 0.00% Added +23.9k +23,860
10 SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio BALA CYNWYD, PA 237,976238.0k $371.2k $371.2k 0.00% Added +28.0k +27,990
11 XTX Topco Ltd 0.01% of their portfolio LONDON, X0 178,303178.3k $278.2k $278.2k 0.01% Added +122.3k +122,291
12 Beartown Capital Management, LLC 0.20% of their portfolio HUNTINGTON WOODS, MI 160,027160.0k $249.6k $249.6k 0.20% First filing
13 TWO SIGMA INVESTMENTS, LP 0.00% of their portfolio NEW YORK, NY 126,160126.2k $196.8k $196.8k 0.00% New
14 STATE STREET CORP 0.00% of their portfolio BOSTON, MA 121,846121.8k $190.1k $190.1k 0.00% Added +8.1k +8,100
15 MARSHALL WACE, LLP 0.00% of their portfolio LONDON, X0 81,01181.0k $126.4k $126.4k 0.00% New
16 ESSEX INVESTMENT MANAGEMENT CO LLC 0.02% of their portfolio BOSTON, MA 77,25077.2k $120.5k $120.5k 0.02% Unchanged
17 INTEGRITY WEALTH ADVISORS, INC. 0.07% of their portfolio Ventura, CA 70,00070.0k $95.2k $95.2k 0.07% Unchanged
18 TWO SIGMA ADVISERS, LP 0.00% of their portfolio NEW YORK, NY 67,50067.5k $105.3k $105.3k 0.00% New
19 DIMENSIONAL FUND ADVISORS LP 0.00% of their portfolio AUSTIN, TX 51,19951.2k $79.7k $79.7k 0.00% Reduced -3.2k -3,202
20 GROUP ONE TRADING LLC 0.00% of their portfolio CHICAGO, IL 42,50942.5k $66.3k $66.3k 0.00% Added +12.3k +12,303
21 AMERICAN CENTURY COMPANIES INC 0.00% of their portfolio KANSAS CITY, MO 38,54338.5k $60.1k $60.1k 0.00% Added +2.0k +1,988
22 GSA CAPITAL PARTNERS LLP 0.00% of their portfolio LONDON, X0 32,01132.0k $50.0k $50.0k 0.00% Reduced -4.5k -4,479
23 NORTHERN TRUST CORP 0.00% of their portfolio CHICAGO, IL 31,43531.4k $49.0k $49.0k 0.00% Unchanged
24 Cresset Asset Management, LLC 0.00% of their portfolio Chicago, IL 25,50025.5k $39.8k $39.8k 0.00% Unchanged
25 Legato Capital Management LLC 0.00% of their portfolio San Francisco, CA 18,16518.2k $28.3k $28.3k 0.00% Unchanged
26 Virtu Financial LLC 0.00% of their portfolio New York, NY 17,25417.3k $27.0k $27.0k 0.00% New
27 TWO SIGMA SECURITIES, LLC 0.00% of their portfolio NEW YORK, NY 14,58314.6k $22.7k $22.7k 0.00% New
28 Covestor Ltd 0.01% of their portfolio LONDON, X0 13,18713.2k $21.0k $21.0k 0.01% Unchanged
29 Quadrature Capital Ltd 0.00% of their portfolio LONDON, X0 11,57911.6k $18.1k $18.1k 0.00% New
30 HighTower Advisors, LLC 0.00% of their portfolio CHICAGO, IL 10,44010.4k $16.3k $16.3k 0.00% Added +40 +40
31 Founders Capital Management 0.00% of their portfolio HOUSTON, TX 5,0005.0k $7.8k $7.8k 0.00% Unchanged
32 Tower Research Capital LLC (TRC) 0.00% of their portfolio NEW YORK, NY 4,2884.3k $6.7k $6.7k 0.00% New
33 SIMPLEX TRADING, LLC 0.00% of their portfolio CHICAGO, IL 3,2993.3k $5.1k $5.1k 0.00% Reduced -39.2k -39,202
34 NewEdge Advisors, LLC 0.00% of their portfolio NEW ORLEANS, LA 2,3272.3k $3.6k $3.6k 0.00% Reduced -15.3k -15,326
35 New England Capital Financial Advisors LLC 0.00% of their portfolio MERIDEN, CT 2,0002.0k $3.1k $3.1k 0.00% Unchanged
36 OSAIC HOLDINGS, INC. 0.00% of their portfolio SCOTTSDALE, AZ 1,2001.2k $1.9k $1.9k 0.00% Unchanged
37 WELLS FARGO & COMPANY/MN 0.00% of their portfolio SAN FRANCISCO, CA 1,1501.1k $1.8k $1.8k 0.00% Reduced -2.5k -2,500
38 SBI Securities Co., Ltd. 0.00% of their portfolio TOKYO, M0 719719 $1.1k $1.1k 0.00% Reduced -110 -110
39 Steward Partners Investment Advisory, LLC 0.00% of their portfolio STAMFORD, CT 600600 $936 $936 0.00% Unchanged
40 Wilmington Savings Fund Society, FSB 0.00% of their portfolio WILMINGTON, DE 500500 $780 $780 0.00% Unchanged
41 BANK OF AMERICA CORP /DE/ 0.00% of their portfolio CHARLOTTE, NC 280280 $437 $437 0.00% Added +63 +63
42 CKW FINANCIAL GROUP 0.00% of their portfolio HONOLULU, HI 200200 $0 $0 0.00% Unchanged
43 Motiv8 Investments LLC 0.00% of their portfolio PORT ST. LUCIE, FL 100100 $0 $0 0.00% New
44 MORGAN STANLEY 0.00% of their portfolio NEW YORK, NY 2121 $33 $33 0.00% New
45 FMR LLC 0.00% of their portfolio BOSTON, MA 1818 $28 $28 0.00% New