FuelCell Energy, Inc.
BG ˙ BUL ˙ US35952H6018
SecurityBG:FEY / FuelCell Energy, Inc.
InstitutionCitadel Advisors Llc
ManagerKen Griffin
Latest Disclosed Ownership570,289 shares
Latest Disclosed Value $ 3,723,987
Citadel Advisors Llc ownership in FEY / FuelCell Energy, Inc.

On May 15, 2026 - Citadel Advisors Llc filed a 13F-HR form disclosing ownership of 570,289 shares of FuelCell Energy, Inc. (BG:FEY) valued at $3,723,987 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 203,964 shares of FuelCell Energy, Inc.. This represents a change in shares of 179.60% during the quarter.

Citadel Advisors Llc has a history of taking positions in derivatives of the underlying security (FEY) in the form of stock options. The firm currently holds call options representing 1,068,239 of underlying shares valued at $6,975,601 USD and put options representing 120,100 of underlying shares valued at $784,253 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

BG:FEY / FuelCell Energy, Inc. Historical Put/Call Ratio
Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date
Effective
Date
Form Security Class ID Avg Price
Paid (Est)
Reported
Shares
ΔShares ΔShares
(%)
Reported
Value
(x1000)
ΔValue
(%)
Alloc
(%)
ΔAlloc ΔAlloc (%) Cost Basis
(x1000)
Unrealized
Gain/Loss
(x1000)
2026-05-15 2026-03-31 13F FUELCELL ENERGY COM NEW 35952H700 570,289 366,325 179.60 3,724 149.87 0.0005
2026-02-17 2025-12-31 13F FUELCELL ENERGY COM NEW 35952H700 203,964 157,307 337.16 1,491 310.47 0.0002
2025-11-14 2025-09-30 13F FUELCELL ENERGY COM NEW 35952H700 46,657 46,657 364 0.0001
2025-05-15 2025-03-31 13F FUELCELL ENERGY COM NEW 35952H700 0 -1,032 -100.00 0 -100.00
2025-02-14 2024-12-31 13F FUELCELL ENERGY COM NEW 35952H700 1,032 -84,704 -98.80 9 -57.14 0.0000
2019-05-15 2019-03-31 13F FUELCELL ENERGY Cmn 35952H502 85,736 -90,757 -51.42 21 -78.35 0.0000
2019-02-14 2018-12-31 13F FUELCELL ENERGY Cmn 35952H502 176,493 60,722 52.45 97 -21.77 0.0001
2018-11-13 2018-09-30 13F FUELCELL ENERGY Cmn 35952H502 115,771 99,415 607.82 124 463.64 0.0001
2018-08-14 2018-06-30 13F/A-1 FUELCELL ENERGY Cmn 35952H502 16,356 16,356 -85.87 22 -82.26 0.0000
2018-08-10 2018-06-30 13F FUELCELL ENERGY Cmn 35952H502 16,356 16,356 22
2018-05-14 2018-03-31 13F/A-1 FUELCELL ENERGY Cmn 35952H502 0 -22,482 -100.00 0 -100.00
2018-02-09 2017-12-31 13F FUELCELL ENERGY Cmn 35952H502 22,482 22,482 38 0.0000
2017-02-10 2016-12-31 13F FUELCELL ENERGY INC. CMN STK Cmn 35952H502 0 -15,986 -100.00 0 -100.00
2017-01-31 2016-09-30 13F/A-1 FUELCELL ENERGY Cmn 35952H502 15,986 -27,688 -63.40 87 -68.01 0.0001
2016-11-10 2016-09-30 13F FUELCELL ENERGY INC. CMN STK Cmn 35952H502 15,986 87
2017-01-31 2016-06-30 13F/A-1 FUELCELL ENERGY Cmn 35952H502 43,674 43,674 272 0.0003
2016-08-12 2016-06-30 13F FUELCELL ENERGY INC. CMN STK Cmn 35952H502 43,674 272
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-15 2026-03-31 13F FUELCELL ENERGY COM NEW Call 1,068,239 42.42 6,976 27.21 n/a n/a n/a
2026-02-17 2025-12-31 13F FUELCELL ENERGY COM NEW Call 750,076 43.62 5,483 34.62 n/a n/a n/a
2025-11-14 2025-09-30 13F FUELCELL ENERGY COM NEW Call 522,268 88.16 4,074 161.59 n/a n/a n/a
2025-08-14 2025-06-30 13F FUELCELL ENERGY COM NEW Call 277,569 -2.31 1,557 19.40 n/a n/a n/a
2025-05-15 2025-03-31 13F FUELCELL ENERGY COM NEW Call 284,123 -26.49 1,304 -62.68 n/a n/a n/a
2025-02-14 2024-12-31 13F FUELCELL ENERGY COM NEW Call 386,532 481.25 3,494 21,737.50 n/a n/a n/a
2019-05-15 2019-03-31 13F FUELCELL ENERGY Cmn Call 66,500 47.12 16 -36.00 n/a n/a n/a
2019-02-14 2018-12-31 13F FUELCELL ENERGY Cmn Call 45,200 -29.49 25 -63.77 n/a n/a n/a
2018-11-13 2018-09-30 13F FUELCELL ENERGY Cmn Call 64,100 62.69 69 32.69 n/a n/a n/a
2018-08-14 2018-06-30 13F/A FUELCELL ENERGY Cmn Call 39,400 -57.73 52 -67.70 n/a n/a n/a
2018-08-10 2018-06-30 13F FUELCELL ENERGY Cmn Call 39,400 52 n/a n/a n/a
2018-05-14 2018-03-31 13F/A FUELCELL ENERGY Cmn Call 93,200 217.01 161 222.00 n/a n/a n/a
2018-05-11 2018-03-31 13F FUELCELL ENERGY Cmn Call 93,200 161 n/a n/a n/a
2018-02-09 2017-12-31 13F FUELCELL ENERGY Cmn Call 29,400 -64.32 50 -65.28 n/a n/a n/a
2017-11-09 2017-09-30 13F FUELCELL ENERGY Cmn Call 82,400 10.01 144 54.84 n/a n/a n/a
2017-08-11 2017-06-30 13F FUELCELL ENERGY Cmn Call 74,900 194.88 93 165.71 n/a n/a n/a
2017-05-12 2017-03-31 13F FUELCELL ENERGY Cmn Call 25,400 -49.50 35 -60.23 n/a n/a n/a
2017-02-10 2016-12-31 13F FUELCELL ENERGY Cmn Call 50,300 -35.35 88 -79.15 n/a n/a n/a
2017-01-31 2016-09-30 13F/A FUELCELL ENERGY Cmn Call 77,800 50.78 422 31.46 n/a n/a n/a
2016-11-10 2016-09-30 13F FUELCELL ENERGY INC. CMN STK Cmn Call 77,800 422 n/a n/a n/a
2017-01-31 2016-06-30 13F/A FUELCELL ENERGY Cmn Call 51,600 6.83 321 -1.83 n/a n/a n/a
2016-08-12 2016-06-30 13F FUELCELL ENERGY INC. CMN STK Cmn Call 51,600 321 n/a n/a n/a
2017-01-31 2016-03-31 13F/A FUELCELL ENERGY Cmn Call 48,300 277.34 327 419.05 n/a n/a n/a
2016-05-13 2016-03-31 13F FUELCELL ENERGY Cmn Call 48,300 327 n/a n/a n/a
2017-01-31 2015-12-31 13F/A FUELCELL ENERGY Cmn Call 12,800 -73.33 63 80.00 n/a n/a n/a
2016-02-12 2015-12-31 13F FUELCELL ENERGY Cmn Call 12,800 63 n/a n/a n/a
2015-11-16 2015-09-30 13F FUELCELL ENERGY Cmn Call 48,000 110.53 35 59.09 n/a n/a n/a
2015-08-14 2015-06-30 13F FUELCELL ENERGY INC. CMN STK Cmn Call 22,800 -43.70 22 -56.86 n/a n/a n/a
2015-05-15 2015-03-31 13F FUELCELL ENERGY INC. CMN STK Cmn Call 40,500 -26.23 51 -40.00 n/a n/a n/a
2015-02-17 2014-12-31 13F FUELCELL ENERGY INC. CMN STK Cmn Call 54,900 -29.71 85 -47.85 n/a n/a n/a
2014-11-14 2014-09-30 13F FUELCELL ENERGY Cmn Call 78,100 -26.18 163 -35.83 n/a n/a n/a
2014-08-14 2014-06-30 13F FUELCELL ENERGY Cmn Call 105,800 195.53 254 185.39 n/a n/a n/a
2014-05-15 2014-03-31 13F FUELCELL ENERGY INC. CMN STK Cmn Call 35,800 228.44 89 535.71 n/a n/a n/a
2013-11-14 2013-09-30 13F FUELCELL ENERGY INC. CMN STK Cmn Call 10,900 -25.34 14 -26.32 n/a n/a n/a
2013-08-14 2013-06-30 13F FUELCELL ENERGY INC. CMN STK Cmn Call 14,600 19 n/a n/a n/a
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-15 2026-03-31 13F FUELCELL ENERGY COM NEW Put 120,100 -41.39 784 -47.63 n/a n/a n/a
2026-02-17 2025-12-31 13F FUELCELL ENERGY COM NEW Put 204,900 -37.34 1,498 -41.29 n/a n/a n/a
2025-11-14 2025-09-30 13F FUELCELL ENERGY COM NEW Put 327,000 122.15 2,551 209.09 n/a n/a n/a
2025-08-14 2025-06-30 13F FUELCELL ENERGY COM NEW Put 147,200 64.88 826 101.71 n/a n/a n/a
2025-05-15 2025-03-31 13F FUELCELL ENERGY COM NEW Put 89,279 71.83 410 -12.79 n/a n/a n/a
2025-02-14 2024-12-31 13F FUELCELL ENERGY COM NEW Put 51,958 470 n/a n/a n/a
2019-08-14 2019-06-30 13F FUELCELL ENERGY Cmn Put 0 -100.00 0 -100.00 n/a n/a n/a
2019-05-15 2019-03-31 13F FUELCELL ENERGY Cmn Put 67,600 -53.38 17 -78.75 n/a n/a n/a
2019-02-14 2018-12-31 13F FUELCELL ENERGY Cmn Put 145,000 -27.79 80 -62.79 n/a n/a n/a
2018-11-13 2018-09-30 13F FUELCELL ENERGY Cmn Put 200,800 49.07 215 20.79 n/a n/a n/a
2018-08-14 2018-06-30 13F/A FUELCELL ENERGY Cmn Put 134,700 232.59 178 154.29 n/a n/a n/a
2018-08-10 2018-06-30 13F FUELCELL ENERGY Cmn Put 134,700 178 n/a n/a n/a
2018-05-14 2018-03-31 13F/A FUELCELL ENERGY Cmn Put 40,500 -20.43 70 -19.54 n/a n/a n/a
2018-05-11 2018-03-31 13F FUELCELL ENERGY Cmn Put 40,500 70 n/a n/a n/a
2018-02-09 2017-12-31 13F FUELCELL ENERGY Cmn Put 50,900 25.68 87 24.29 n/a n/a n/a
2017-11-09 2017-09-30 13F FUELCELL ENERGY Cmn Put 0 -100.00 0 -100.00 n/a n/a n/a
2017-08-11 2017-06-30 13F FUELCELL ENERGY Cmn Put 23,400 16.42 29 3.57 n/a n/a n/a
2017-05-12 2017-03-31 13F FUELCELL ENERGY Cmn Put 20,100 53.44 28 21.74 n/a n/a n/a
2017-02-10 2016-12-31 13F FUELCELL ENERGY Cmn Put 13,100 -7.09 23 -69.74 n/a n/a n/a
2017-01-31 2016-09-30 13F/A FUELCELL ENERGY Cmn Put 14,100 -63.66 76 -68.46 n/a n/a n/a
2016-11-10 2016-09-30 13F FUELCELL ENERGY INC. CMN STK Cmn Put 14,100 76 n/a n/a n/a
2017-01-31 2016-06-30 13F/A FUELCELL ENERGY Cmn Put 38,800 175.18 241 217.11 n/a n/a n/a
2016-08-12 2016-06-30 13F FUELCELL ENERGY INC. CMN STK Cmn Put 38,800 241 n/a n/a n/a
2017-01-31 2016-03-31 13F/A FUELCELL ENERGY Cmn Put 0 -100.00 0 -100.00 n/a n/a n/a
2017-01-31 2015-12-31 13F/A FUELCELL ENERGY Cmn Put 2,800 -95.84 14 -71.43 n/a n/a n/a
2016-02-12 2015-12-31 13F FUELCELL ENERGY Cmn Put 2,800 14 n/a n/a n/a
2015-11-16 2015-09-30 13F FUELCELL ENERGY Cmn Put 67,300 -49.78 49 -62.60 n/a n/a n/a
2015-08-14 2015-06-30 13F FUELCELL ENERGY INC. CMN STK Cmn Put 134,000 43.62 131 11.97 n/a n/a n/a
2015-05-15 2015-03-31 13F FUELCELL ENERGY INC. CMN STK Cmn Put 93,300 -23.08 117 -37.43 n/a n/a n/a
2015-02-17 2014-12-31 13F FUELCELL ENERGY INC. CMN STK Cmn Put 121,300 0.83 187 -25.50 n/a n/a n/a
2014-11-14 2014-09-30 13F FUELCELL ENERGY Cmn Put 120,300 4.88 251 -8.73 n/a n/a n/a
2014-08-14 2014-06-30 13F FUELCELL ENERGY Cmn Put 114,700 -37.36 275 -39.43 n/a n/a n/a
2014-05-15 2014-03-31 13F FUELCELL ENERGY INC. CMN STK Cmn Put 183,100 60.33 454 181.99 n/a n/a n/a
2014-02-14 2013-12-31 13F FUELCELL ENERGY INC. CMN STK Cmn Put 114,200 162.53 161 187.50 n/a n/a n/a
2013-11-14 2013-09-30 13F FUELCELL ENERGY INC. CMN STK Cmn Put 43,500 2.11 56 3.70 n/a n/a n/a
2013-08-14 2013-06-30 13F FUELCELL ENERGY INC. CMN STK Cmn Put 42,600 54 n/a n/a n/a
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.