Golub Capital BDC, Inc.
US ˙ NasdaqGS ˙ US38173M1027

SecurityGBDC / Golub Capital BDC, Inc.
InstitutionSimplex Trading, Llc
Latest Disclosed Ownership0 shares
Latest Disclosed Value $ 0
Simplex Trading, Llc ownership in GBDC / Golub Capital BDC, Inc.

On February 11, 2026 - Simplex Trading, Llc filed a 13F-HR form disclosing ownership of 0 shares of Golub Capital BDC, Inc. (US:GBDC) valued at $0 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 12, 2025 disclosing 2,346 shares of Golub Capital BDC, Inc.. The current value of the position is $0 USD.

Simplex Trading, Llc has a history of taking positions in derivatives of the underlying security (GBDC) in the form of stock options. The firm currently holds call options representing 2,300 of underlying shares valued at $29,118 USD and put options representing 7,000 of underlying shares valued at $88,620 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.

GBDC / Golub Capital BDC, 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)
2026-02-11 2025-12-31 13F GOLUB CAP BDC COM 38173M102 0 -2,346 -100.00 0 0.0000
2025-11-12 2025-09-30 13F GOLUB CAP BDC COM 38173M102 2,346 1,874 397.03 0 0.0000
2025-08-05 2025-06-30 13F GOLUB CAP BDC COM 38173M102 472 -8,214 -94.57 0 0.0000
2025-05-12 2025-03-31 13F GOLUB CAP BDC COM 38173M102 8,686 4,129 90.61 0 0.0001
2025-02-11 2024-12-31 13F GOLUB CAP BDC COM 38173M102 4,557 4,557 0 0.0000
2023-11-01 2023-09-30 13F GOLUB CAP BDC COM 38173M102 0 -2,456 -100.00 0 0.0000
2023-08-04 2023-06-30 13F GOLUB CAP BDC COM 38173M102 2,456 2,269 1,213.37 0 0.0000
2023-04-27 2023-03-31 13F GOLUB CAP BDC COM 38173M102 187 187 0 0.0000
2022-11-04 2022-09-30 13F GOLUB CAP BDC COM 38173M102 0 -7,524 -100.00 0 -100.00
2022-08-03 2022-06-30 13F GOLUB CAP BDC COM 38173M102 7,524 5,869 354.62 97 288.00 0.0001
2022-05-02 2022-03-31 13F GOLUB CAP BDC COM 38173M102 1,655 1,655 25 0.0000
2020-07-13 2020-06-30 13F GOLUB CAP BDC COM 38173M102 0 -200 -100.00 0 -100.00
2020-04-29 2020-03-31 13F GOLUB CAP BDC COM 38173M102 200 200 2 0.0000
2019-04-18 2019-03-31 13F GOLUB CAP BDC COM 38173M102 0 -160 -100.00 0 -100.00
2019-01-16 2018-12-31 13F GOLUB CAP BDC COM 38173M102 160 160 2 0.0000
2017-10-25 2017-09-30 13F GOLUB CAP BDC COM 38173M102 0 -75 -100.00 0 -100.00
2017-07-12 2017-06-30 13F GOLUB CAP BDC COM 38173M102 75 -96 -56.14 1 -66.67 0.0000
2017-04-21 2017-03-31 13F GOLUB CAP BDC COM 38173M102 171 171 128.00 3 200.00 0.0001
2017-01-11 2016-12-31 13F GOLUB CAP BDC COM 38173M102 0 -324 -100.00 0 -100.00
2016-10-07 2016-09-30 13F GOLUB CAP BDC COM 38173M102 324 324 0.00 6 0.0004
2016-01-20 2015-12-31 13F GOLUB CAP BDC COM 38173M102 0 -4 -100.00 0 -100.00 0.0000
2015-10-08 2015-09-30 13F GOLUB CAP BDC COM 38173M102 4 4 0 0.0000
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
(%)
2026-05-14 2026-03-31 13F GOLUB CAP BDC CALL Call 2,300 -51.06 29 -53.97 n/a n/a n/a
2026-02-11 2025-12-31 13F GOLUB CAP BDC CALL Call 4,700 -11.32 64 n/a n/a n/a
2025-11-12 2025-09-30 13F GOLUB CAP BDC CALL Call 5,300 70.97 0 n/a n/a n/a
2025-08-05 2025-06-30 13F GOLUB CAP BDC CALL Call 3,100 -53.03 0 n/a n/a n/a
2025-05-12 2025-03-31 13F GOLUB CAP BDC CALL Call 6,600 40.43 0 n/a n/a n/a
2025-02-11 2024-12-31 13F GOLUB CAP BDC CALL Call 4,700 -69.48 0 n/a n/a n/a
2024-11-08 2024-09-30 13F GOLUB CAP BDC CALL Call 15,400 10.00 0 n/a n/a n/a
2024-07-25 2024-06-30 13F GOLUB CAP BDC CALL Call 14,000 366.67 0 n/a n/a n/a
2024-04-25 2024-03-31 13F GOLUB CAP BDC CALL Call 3,000 -56.52 0 n/a n/a n/a
2024-02-02 2023-12-31 13F GOLUB CAP BDC CALL Call 6,900 102.94 0 n/a n/a n/a
2023-11-01 2023-09-30 13F GOLUB CAP BDC CALL Call 3,400 209.09 0 n/a n/a n/a
2023-08-04 2023-06-30 13F GOLUB CAP BDC CALL Call 1,100 450.00 0 n/a n/a n/a
2023-04-27 2023-03-31 13F GOLUB CAP BDC CALL Call 200 -99.72 0 n/a n/a n/a
2023-02-02 2022-12-31 13F GOLUB CAP BDC CALL Call 71,800 -0.97 1 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F GOLUB CAP BDC CALL Call 72,500 14,400.00 898 14,866.67 n/a n/a n/a
2022-08-03 2022-06-30 13F GOLUB CAP BDC CALL Call 500 0.00 6 -14.29 n/a n/a n/a
2022-05-02 2022-03-31 13F GOLUB CAP BDC CALL Call 500 -37.50 7 -41.67 n/a n/a n/a
2022-02-23 2021-12-31 13F/A GOLUB CAP BDC CALL Call 800 -46.67 12 -47.83 n/a n/a n/a
2022-02-04 2021-12-31 13F GOLUB CAP BDC CALL Call 1,500 23 n/a n/a n/a
2021-10-28 2021-09-30 13F GOLUB CAP BDC CALL Call 1,500 25.00 23 27.78 n/a n/a n/a
2021-08-12 2021-06-30 13F GOLUB CAP BDC CALL Call 1,200 2,900.00 18 -68.97 n/a n/a n/a
2021-04-26 2021-03-31 13F GOLUB CAP BDC CALL Call 40 -54.55 58 -53.23 n/a n/a n/a
2021-02-02 2020-12-31 13F GOLUB CAP BDC CALL Call 88 -29.03 124 -24.39 n/a n/a n/a
2020-10-14 2020-09-30 13F GOLUB CAP BDC CALL Call 124 87.88 164 115.79 n/a n/a n/a
2020-07-13 2020-06-30 13F GOLUB CAP BDC CALL Call 66 3,200.00 76 3,700.00 n/a n/a n/a
2020-04-29 2020-03-31 13F GOLUB CAP BDC CALL Call 2 -96.97 2 -97.37 n/a n/a n/a
2019-10-15 2019-09-30 13F GOLUB CAP BDC CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2019-07-26 2019-06-30 13F GOLUB CAP BDC CALL Call 20 0.00 35 0.00 n/a n/a n/a
2019-04-18 2019-03-31 13F GOLUB CAP BDC CALL Call 20 0.00 35 0.00 n/a n/a n/a
2018-07-30 2018-06-30 13F GOLUB CAP BDC CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2018-04-26 2018-03-31 13F GOLUB CAP BDC CALL Call 15 0.00 0 n/a n/a n/a
2018-01-10 2017-12-31 13F GOLUB CAP BDC CALL Call 15 0.00 0 n/a n/a n/a
2017-10-25 2017-09-30 13F GOLUB CAP BDC CALL Call 0 -100.00 0 n/a n/a n/a
2017-07-12 2017-06-30 13F GOLUB CAP BDC CALL Call 20 0.00 0 n/a n/a n/a
2017-04-21 2017-03-31 13F GOLUB CAP BDC CALL Call 0 -100.00 0 n/a n/a n/a
2017-01-11 2016-12-31 13F GOLUB CAP BDC CALL Call 7 0.00 0 n/a n/a n/a
2016-10-07 2016-09-30 13F GOLUB CAP BDC CALL Call 7 -91.46 0 -100.00 n/a n/a n/a
2016-07-18 2016-06-30 13F GOLUB CAP BDC CALL Call 82 720.00 6 n/a n/a n/a
2016-04-14 2016-03-31 13F GOLUB CAP BDC CALL Call 10 0 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
(%)
2026-05-14 2026-03-31 13F GOLUB CAP BDC PUT Put 7,000 -35.78 89 -40.14 n/a n/a n/a
2026-02-11 2025-12-31 13F GOLUB CAP BDC PUT Put 10,900 81.67 148 n/a n/a n/a
2025-11-12 2025-09-30 13F GOLUB CAP BDC PUT Put 6,000 275.00 0 n/a n/a n/a
2025-08-05 2025-06-30 13F GOLUB CAP BDC PUT Put 1,600 -87.10 0 n/a n/a n/a
2025-05-12 2025-03-31 13F GOLUB CAP BDC PUT Put 12,400 -6.06 0 n/a n/a n/a
2025-02-11 2024-12-31 13F GOLUB CAP BDC PUT Put 13,200 33.33 0 n/a n/a n/a
2024-11-08 2024-09-30 13F GOLUB CAP BDC PUT Put 9,900 312.50 0 n/a n/a n/a
2024-07-25 2024-06-30 13F GOLUB CAP BDC PUT Put 2,400 500.00 0 n/a n/a n/a
2024-04-25 2024-03-31 13F GOLUB CAP BDC PUT Put 400 -33.33 0 n/a n/a n/a
2024-02-02 2023-12-31 13F GOLUB CAP BDC PUT Put 600 20.00 0 n/a n/a n/a
2023-11-01 2023-09-30 13F GOLUB CAP BDC PUT Put 500 -86.84 0 n/a n/a n/a
2023-08-04 2023-06-30 13F GOLUB CAP BDC PUT Put 3,800 280.00 0 n/a n/a n/a
2023-04-27 2023-03-31 13F GOLUB CAP BDC PUT Put 1,000 400.00 0 n/a n/a n/a
2023-02-02 2022-12-31 13F GOLUB CAP BDC PUT Put 200 100.00 0 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F GOLUB CAP BDC PUT Put 100 -99.35 1 -99.50 n/a n/a n/a
2022-08-03 2022-06-30 13F GOLUB CAP BDC PUT Put 15,500 3,775.00 200 3,233.33 n/a n/a n/a
2022-05-02 2022-03-31 13F GOLUB CAP BDC PUT Put 400 33.33 6 50.00 n/a n/a n/a
2022-02-23 2021-12-31 13F/A GOLUB CAP BDC PUT Put 300 -66.67 4 -69.23 n/a n/a n/a
2022-02-04 2021-12-31 13F GOLUB CAP BDC PUT Put 900 13 n/a n/a n/a
2021-10-28 2021-09-30 13F GOLUB CAP BDC PUT Put 900 0.00 13 0.00 n/a n/a n/a
2021-08-12 2021-06-30 13F GOLUB CAP BDC PUT Put 900 9,900.00 13 0.00 n/a n/a n/a
2021-04-26 2021-03-31 13F GOLUB CAP BDC PUT Put 9 -92.44 13 -92.26 n/a n/a n/a
2021-02-02 2020-12-31 13F GOLUB CAP BDC PUT Put 119 9.17 168 16.67 n/a n/a n/a
2020-10-14 2020-09-30 13F GOLUB CAP BDC PUT Put 109 118.00 144 148.28 n/a n/a n/a
2020-07-13 2020-06-30 13F GOLUB CAP BDC PUT Put 50 1,566.67 58 1,833.33 n/a n/a n/a
2020-04-29 2020-03-31 13F GOLUB CAP BDC PUT Put 3 -94.00 3 -94.83 n/a n/a n/a
2019-10-15 2019-09-30 13F GOLUB CAP BDC PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2019-07-26 2019-06-30 13F GOLUB CAP BDC PUT Put 1 -75.00 1 -85.71 n/a n/a n/a
2019-04-18 2019-03-31 13F GOLUB CAP BDC PUT Put 4 33.33 7 75.00 n/a n/a n/a
2019-01-16 2018-12-31 13F GOLUB CAP BDC PUT Put 3 -25.00 4 -42.86 n/a n/a n/a
2017-10-25 2017-09-30 13F GOLUB CAP BDC PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2017-07-12 2017-06-30 13F GOLUB CAP BDC PUT Put 7 0.00 0 n/a n/a n/a
2017-04-21 2017-03-31 13F GOLUB CAP BDC PUT Put 7 0.00 0 n/a n/a n/a
2017-01-11 2016-12-31 13F GOLUB CAP BDC PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2016-10-07 2016-09-30 13F GOLUB CAP BDC PUT Put 50 1 n/a n/a n/a
2016-07-18 2016-06-30 13F GOLUB CAP BDC PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2016-04-14 2016-03-31 13F GOLUB CAP BDC PUT Put 1 0 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.