Bain Capital Specialty Finance, Inc.
US ˙ NYSE ˙ US05684B1070

SecurityBCSF / Bain Capital Specialty Finance, Inc.
InstitutionSimplex Trading, Llc
Latest Disclosed Ownership5 shares
Latest Disclosed Value $ 62
Simplex Trading, Llc ownership in BCSF / Bain Capital Specialty Finance, Inc.

On May 14, 2026 - Simplex Trading, Llc filed a 13F-HR form disclosing ownership of 5 shares of Bain Capital Specialty Finance, Inc. (US:BCSF) valued at $62 USD as of March 31, 2026. The entity filed a previous 13F-HR on May 12, 2025 disclosing 0 shares of Bain Capital Specialty Finance, Inc.. The current value of the position is $64 USD.

Simplex Trading, Llc has a history of taking positions in derivatives of the underlying security (BCSF) in the form of stock options. The firm currently holds call options representing 1,200 of underlying shares valued at $14,880 USD and put options representing 0 of underlying shares valued at $0 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.

BCSF / Bain Capital Specialty Finance, 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)
2026-05-14 2026-03-31 13F BAIN CAP SPECIALTY FIN COM 05684B107 5 5 0 0.0000
2025-05-12 2025-03-31 13F BAIN CAP SPECIALTY FIN COM 05684B107 0 -599 -100.00 0 0.0000
2025-02-11 2024-12-31 13F BAIN CAP SPECIALTY FIN COM 05684B107 599 599 0 0.0000
2023-11-01 2023-09-30 13F BAIN CAP SPECIALTY FIN COM 05684B107 0 -15,059 -100.00 0 0.0000
2023-08-04 2023-06-30 13F BAIN CAP SPECIALTY FIN COM 05684B107 15,059 -10,163 -40.29 0 0.0002
2023-04-27 2023-03-31 13F BAIN CAP SPECIALTY FIN COM 05684B107 25,222 -31,266 -55.35 0 0.0003
2023-02-02 2022-12-31 13F BAIN CAP SPECIALTY FIN COM 05684B107 56,488 29,930 112.70 1 -100.00 0.0007
2022-11-04 2022-09-30 13F BAIN CAP SPECIALTY FIN COM 05684B107 26,558 20,411 332.05 318 283.13 0.0004
2022-08-03 2022-06-30 13F BAIN CAP SPECIALTY FIN COM 05684B107 6,147 6,147 83 0.0001
2022-05-02 2022-03-31 13F BAIN CAP SPECIALTY FIN COM 05684B107 0 -1,854 -100.00 0 -100.00
2022-02-23 2021-12-31 13F/A-1 BAIN CAP SPECIALTY FIN COM 05684B107 1,854 1,814 4,535.00 28 0.0000
2022-02-04 2021-12-31 13F BAIN CAP SPECIALTY FIN COM 05684B107 40 0 0 0.0000
2021-10-28 2021-09-30 13F BAIN CAP SPECIALTY FIN COM 05684B107 40 0 0.00 0 0.0000
2021-08-12 2021-06-30 13F BAIN CAP SPECIALTY FIN COM 05684B107 40 40 0 0.0000
2021-04-26 2021-03-31 13F BAIN CAP SPECIALTY FIN COM 05684B107 0 -4,741 -100.00 0 -100.00
2021-02-02 2020-12-31 13F BAIN CAP SPECIALTY FIN COM 05684B107 4,741 2,433 105.42 57 147.83 0.0001
2020-10-14 2020-09-30 13F BAIN CAP SPECIALTY FIN COM 05684B107 2,308 1,599 225.53 23 228.57 0.0000
2020-07-13 2020-06-30 13F BAIN CAP SPECIALTY FIN COM 05684B107 709 -10,719 -93.80 7 -93.33 0.0000
2020-04-29 2020-03-31 13F BAIN CAP SPECIALTY FIN COM 05684B107 11,428 6,735 143.51 105 14.13 0.0002
2020-02-05 2019-12-31 13F BAIN CAP SPECIALTY FIN COM 05684B107 4,693 4,693 92 0.0002
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 BAIN CAP SPECIALTY FIN CALL Call 1,200 -89.19 15 -90.91 n/a n/a n/a
2026-02-11 2025-12-31 13F BAIN CAP SPECIALTY FIN CALL Call 11,100 2.78 154 n/a n/a n/a
2025-11-12 2025-09-30 13F BAIN CAP SPECIALTY FIN CALL Call 10,800 -39.66 0 n/a n/a n/a
2025-08-05 2025-06-30 13F BAIN CAP SPECIALTY FIN CALL Call 17,900 -50.69 0 n/a n/a n/a
2025-05-12 2025-03-31 13F BAIN CAP SPECIALTY FIN CALL Call 36,300 1,916.67 1 n/a n/a n/a
2025-02-11 2024-12-31 13F BAIN CAP SPECIALTY FIN CALL Call 1,800 -50.00 0 n/a n/a n/a
2024-11-08 2024-09-30 13F BAIN CAP SPECIALTY FIN CALL Call 3,600 -52.63 0 n/a n/a n/a
2024-07-25 2024-06-30 13F BAIN CAP SPECIALTY FIN CALL Call 7,600 245.45 0 n/a n/a n/a
2024-04-25 2024-03-31 13F BAIN CAP SPECIALTY FIN CALL Call 2,200 144.44 0 n/a n/a n/a
2024-02-02 2023-12-31 13F BAIN CAP SPECIALTY FIN CALL Call 900 -93.23 0 n/a n/a n/a
2023-11-01 2023-09-30 13F BAIN CAP SPECIALTY FIN CALL Call 13,300 -69.57 0 n/a n/a n/a
2023-08-04 2023-06-30 13F BAIN CAP SPECIALTY FIN CALL Call 43,700 17.16 1 n/a n/a n/a
2023-04-27 2023-03-31 13F BAIN CAP SPECIALTY FIN CALL Call 37,300 856.41 0 n/a n/a n/a
2023-02-02 2022-12-31 13F BAIN CAP SPECIALTY FIN CALL Call 3,900 -20.41 0 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F BAIN CAP SPECIALTY FIN CALL Call 4,900 11.36 58 -1.69 n/a n/a n/a
2022-08-03 2022-06-30 13F BAIN CAP SPECIALTY FIN CALL Call 4,400 -49.43 59 -56.30 n/a n/a n/a
2022-05-02 2022-03-31 13F BAIN CAP SPECIALTY FIN CALL Call 8,700 987.50 135 1,025.00 n/a n/a n/a
2022-02-23 2021-12-31 13F/A BAIN CAP SPECIALTY FIN CALL Call 800 100.00 12 100.00 n/a n/a n/a
2022-02-04 2021-12-31 13F BAIN CAP SPECIALTY FIN CALL Call 400 6 n/a n/a n/a
2021-10-28 2021-09-30 13F BAIN CAP SPECIALTY FIN CALL Call 400 0.00 6 0.00 n/a n/a n/a
2021-08-12 2021-06-30 13F BAIN CAP SPECIALTY FIN CALL Call 400 339.56 6 -95.52 n/a n/a n/a
2021-04-26 2021-03-31 13F BAIN CAP SPECIALTY FIN CALL Call 91 -44.17 134 -31.98 n/a n/a n/a
2021-02-02 2020-12-31 13F BAIN CAP SPECIALTY FIN CALL Call 163 16,200.00 197 19,600.00 n/a n/a n/a
2020-10-14 2020-09-30 13F BAIN CAP SPECIALTY FIN CALL Call 1 -66.67 1 -66.67 n/a n/a n/a
2020-07-13 2020-06-30 13F BAIN CAP SPECIALTY FIN CALL Call 3 200.00 3 200.00 n/a n/a n/a
2020-04-28 2020-03-31 13F BAIN CAP SPECIALTY FIN CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2020-02-05 2019-12-31 13F BAIN CAP SPECIALTY FIN CALL Call 1 1 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 BAIN CAP SPECIALTY FIN PUT Put 0 -100.00 0 n/a n/a n/a
2026-02-11 2025-12-31 13F BAIN CAP SPECIALTY FIN PUT Put 1,300 -80.88 18 n/a n/a n/a
2025-11-12 2025-09-30 13F BAIN CAP SPECIALTY FIN PUT Put 6,800 223.81 0 n/a n/a n/a
2025-08-05 2025-06-30 13F BAIN CAP SPECIALTY FIN PUT Put 2,100 -70.00 0 n/a n/a n/a
2025-05-12 2025-03-31 13F BAIN CAP SPECIALTY FIN PUT Put 7,000 6,900.00 0 n/a n/a n/a
2025-02-11 2024-12-31 13F BAIN CAP SPECIALTY FIN PUT Put 100 -91.67 0 n/a n/a n/a
2024-11-08 2024-09-30 13F BAIN CAP SPECIALTY FIN PUT Put 1,200 1,100.00 0 n/a n/a n/a
2024-07-25 2024-06-30 13F BAIN CAP SPECIALTY FIN PUT Put 100 -66.67 0 n/a n/a n/a
2024-04-25 2024-03-31 13F BAIN CAP SPECIALTY FIN PUT Put 300 0 n/a n/a n/a
2024-02-02 2023-12-31 13F BAIN CAP SPECIALTY FIN PUT Put 0 -100.00 0 n/a n/a n/a
2023-11-01 2023-09-30 13F BAIN CAP SPECIALTY FIN PUT Put 19,200 -21.63 0 n/a n/a n/a
2023-08-04 2023-06-30 13F BAIN CAP SPECIALTY FIN PUT Put 24,500 -27.94 0 n/a n/a n/a
2023-04-27 2023-03-31 13F BAIN CAP SPECIALTY FIN PUT Put 34,000 -48.64 0 n/a n/a n/a
2023-02-02 2022-12-31 13F BAIN CAP SPECIALTY FIN PUT Put 66,200 6.43 1 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F BAIN CAP SPECIALTY FIN PUT Put 62,200 842.42 746 738.20 n/a n/a n/a
2022-08-03 2022-06-30 13F BAIN CAP SPECIALTY FIN PUT Put 6,600 0.00 89 -12.75 n/a n/a n/a
2022-05-02 2022-03-31 13F BAIN CAP SPECIALTY FIN PUT Put 6,600 -71.18 102 -70.69 n/a n/a n/a
2022-02-23 2021-12-31 13F/A BAIN CAP SPECIALTY FIN PUT Put 22,900 22,800.00 348 34,700.00 n/a n/a n/a
2022-02-04 2021-12-31 13F BAIN CAP SPECIALTY FIN PUT Put 100 1 n/a n/a n/a
2021-10-28 2021-09-30 13F BAIN CAP SPECIALTY FIN PUT Put 100 0.00 1 0.00 n/a n/a n/a
2021-08-12 2021-06-30 13F BAIN CAP SPECIALTY FIN PUT Put 100 455.56 1 -96.15 n/a n/a n/a
2021-04-26 2021-03-31 13F BAIN CAP SPECIALTY FIN PUT Put 18 -91.43 26 -89.76 n/a n/a n/a
2021-02-02 2020-12-31 13F BAIN CAP SPECIALTY FIN PUT Put 210 2,900.00 254 3,528.57 n/a n/a n/a
2020-10-14 2020-09-30 13F BAIN CAP SPECIALTY FIN PUT Put 7 -96.67 7 -97.24 n/a n/a n/a
2020-07-13 2020-06-30 13F BAIN CAP SPECIALTY FIN PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2020-04-29 2020-03-31 13F BAIN CAP SPECIALTY FIN PUT Put 152 17.83 140 -44.88 n/a n/a n/a
2020-02-05 2019-12-31 13F BAIN CAP SPECIALTY FIN PUT Put 129 254 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.