Main Street Capital Corporation
US ˙ NYSE ˙ US56035L1044

SecurityMAIN / Main Street Capital Corporation
InstitutionSimplex Trading, Llc
Latest Disclosed Ownership480 shares
Latest Disclosed Value $ 25,420
Simplex Trading, Llc ownership in MAIN / Main Street Capital Corporation

On May 14, 2026 - Simplex Trading, Llc filed a 13F-HR form disclosing ownership of 480 shares of Main Street Capital Corporation (US:MAIN) valued at $25,421 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 11, 2026 disclosing 1,723 shares of Main Street Capital Corporation. This represents a change in shares of -72.14% during the quarter. The current value of the position is $24,341 USD.

Simplex Trading, Llc has a history of taking positions in derivatives of the underlying security (MAIN) in the form of stock options. The firm currently holds call options representing 9,000 of underlying shares valued at $476,640 USD and put options representing 25,400 of underlying shares valued at $1,345,184 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.

MAIN / Main Street Capital Corporation 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 MAIN STR CAP COM 56035L104 480 -1,243 -72.14 25 -75.96 0.0000
2026-02-11 2025-12-31 13F MAIN STR CAP COM 56035L104 1,723 1,723 104 0.0001
2025-11-12 2025-09-30 13F MAIN STR CAP COM 56035L104 0 -4,047 -100.00 0 0.0000
2025-08-05 2025-06-30 13F MAIN STR CAP COM 56035L104 4,047 -16,067 -79.88 0 -100.00 0.0001
2025-05-12 2025-03-31 13F MAIN STR CAP COM 56035L104 20,114 20,114 1 0.0007
2023-02-02 2022-12-31 13F MAIN STR CAP COM 56035L104 0 -5,943 -100.00 0 -100.00
2022-11-04 2022-09-30 13F MAIN STR CAP COM 56035L104 5,943 5,943 199 0.0002
2022-05-02 2022-03-31 13F MAIN STR CAP COM 56035L104 0 -6,783 -100.00 0 -100.00
2022-02-04 2021-12-31 13F MAIN STR CAP COM 56035L104 6,783 0 0.00 279 0.00 0.0003
2021-10-28 2021-09-30 13F MAIN STR CAP COM 56035L104 6,783 0 0.00 279 0.36 0.0003
2021-08-12 2021-06-30 13F MAIN STR CAP COM 56035L104 6,783 6,783 278 0.0003
2021-04-26 2021-03-31 13F MAIN STR CAP COM 56035L104 0 -5,789 -100.00 0 -100.00
2021-02-02 2020-12-31 13F MAIN STR CAP COM 56035L104 5,789 -3,154 -35.27 186 -29.55 0.0002
2020-10-14 2020-09-30 13F MAIN STR CAP COM 56035L104 8,943 2,712 43.52 264 36.79 0.0004
2020-07-13 2020-06-30 13F MAIN STR CAP COM 56035L104 6,231 6,231 -30.33 193 -26.89 0.0003
2019-04-18 2019-03-31 13F MAIN STREET CAPITAL COM 56035L104 0 -9,673 -100.00 0 -100.00
2019-01-16 2018-12-31 13F MAIN STREET CAPITAL COM 56035L104 9,673 6,016 164.51 327 133.57 0.0010
2018-10-23 2018-09-30 13F MAIN STREET CAPITAL COM 56035L104 3,657 3,657 -62.19 140 -57.19 0.0004
2018-07-30 2018-06-30 13F MAIN STREET CAPITAL COM 56035L104 0 -16,375 -100.00 0 -100.00
2018-04-26 2018-03-31 13F MAIN STREET CAPITAL COM 56035L104 16,375 15,194 1,286.54 604 1,213.04 0.0266
2018-01-10 2017-12-31 13F MAIN STREET CAPITAL COM 56035L104 1,181 -3,351 -73.94 46 -74.44 0.0020
2017-10-25 2017-09-30 13F MAIN STREET CAPITAL COM 56035L104 4,532 4,279 1,691.30 180 1,900.00 0.0073
2017-07-12 2017-06-30 13F MAIN STREET CAPITAL COM 56035L104 253 253 -94.42 9 -95.00 0.0004
2017-04-21 2017-03-31 13F MAIN STREET CAPITAL COM 56035L104 0 -2,060 -100.00 0 -100.00
2017-01-11 2016-12-31 13F MAIN STREET CAPITAL COM 56035L104 2,060 2,060 75 0.0045
2015-10-08 2015-09-30 13F MAIN STREET CAPITAL COM 56035L104 0 -302 -100.00 0 -100.00
2015-07-08 2015-06-30 13F MAIN STREET CAPITAL COM 56035L104 302 302 9 0.0008
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 MAIN STR CAP CALL Call 9,000 181.25 477 146.63 n/a n/a n/a
2026-02-11 2025-12-31 13F MAIN STR CAP CALL Call 3,200 -73.55 193 n/a n/a n/a
2025-11-12 2025-09-30 13F MAIN STR CAP CALL Call 12,100 -18.79 1 n/a n/a n/a
2025-08-05 2025-06-30 13F MAIN STR CAP CALL Call 14,900 109.86 1 n/a n/a n/a
2025-05-12 2025-03-31 13F MAIN STR CAP CALL Call 7,100 -39.83 0 n/a n/a n/a
2025-02-11 2024-12-31 13F MAIN STR CAP CALL Call 11,800 -4.84 1 n/a n/a n/a
2024-11-08 2024-09-30 13F MAIN STR CAP CALL Call 12,400 -35.75 1 n/a n/a n/a
2024-07-25 2024-06-30 13F MAIN STR CAP CALL Call 19,300 -18.57 1 -100.00 n/a n/a n/a
2024-04-25 2024-03-31 13F MAIN STR CAP CALL Call 23,700 130.10 1 n/a n/a n/a
2024-02-02 2023-12-31 13F MAIN STR CAP CALL Call 10,300 -15.57 0 n/a n/a n/a
2023-11-01 2023-09-30 13F MAIN STR CAP CALL Call 12,200 -61.88 0 -100.00 n/a n/a n/a
2023-08-04 2023-06-30 13F MAIN STR CAP CALL Call 32,000 -50.31 1 -50.00 n/a n/a n/a
2023-04-27 2023-03-31 13F MAIN STR CAP CALL Call 64,400 218.81 3 n/a n/a n/a
2023-02-02 2022-12-31 13F MAIN STR CAP CALL Call 20,200 -63.67 1 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F MAIN STR CAP CALL Call 55,600 -6.87 1,870 -18.70 n/a n/a n/a
2022-08-03 2022-06-30 13F MAIN STR CAP CALL Call 59,700 120.30 2,300 99.13 n/a n/a n/a
2022-05-02 2022-03-31 13F MAIN STR CAP CALL Call 27,100 26.05 1,155 19.81 n/a n/a n/a
2022-02-23 2021-12-31 13F/A MAIN STR CAP CALL Call 21,500 -14.34 964 -6.77 n/a n/a n/a
2022-02-04 2021-12-31 13F MAIN STR CAP CALL Call 25,100 1,034 n/a n/a n/a
2021-10-28 2021-09-30 13F MAIN STR CAP CALL Call 25,100 0.00 1,034 0.29 n/a n/a n/a
2021-08-12 2021-06-30 13F MAIN STR CAP CALL Call 25,100 22,718.18 1,031 139.77 n/a n/a n/a
2021-04-26 2021-03-31 13F MAIN STR CAP CALL Call 110 44.74 430 75.51 n/a n/a n/a
2021-02-02 2020-12-31 13F MAIN STR CAP CALL Call 76 55.10 245 70.14 n/a n/a n/a
2020-10-14 2020-09-30 13F MAIN STR CAP CALL Call 49 -50.51 144 -53.25 n/a n/a n/a
2020-07-13 2020-06-30 13F MAIN STR CAP CALL Call 99 -56.77 308 -34.33 n/a n/a n/a
2020-04-29 2020-03-31 13F MAIN STR CAP CALL Call 229 172.62 469 29.56 n/a n/a n/a
2020-02-05 2019-12-31 13F MAIN STREET CAPITAL CALL Call 84 -11.58 362 -11.71 n/a n/a n/a
2019-10-15 2019-09-30 13F MAIN STREET CAPITAL CALL Call 95 131.71 410 144.05 n/a n/a n/a
2019-07-26 2019-06-30 13F MAIN STREET CAPITAL CALL Call 41 95.24 168 115.38 n/a n/a n/a
2019-04-18 2019-03-31 13F MAIN STREET CAPITAL CALL Call 21 -8.70 78 1.30 n/a n/a n/a
2019-01-16 2018-12-31 13F MAIN STREET CAPITAL CALL Call 23 187.50 77 156.67 n/a n/a n/a
2018-10-23 2018-09-30 13F MAIN STREET CAPITAL CALL Call 8 -60.00 30 -60.53 n/a n/a n/a
2018-07-30 2018-06-30 13F MAIN STREET CAPITAL CALL Call 20 5.26 76 153.33 n/a n/a n/a
2018-04-26 2018-03-31 13F MAIN STREET CAPITAL CALL Call 19 58.33 0 -100.00 n/a n/a n/a
2018-01-10 2017-12-31 13F MAIN STREET CAPITAL CALL Call 12 33.33 0 n/a n/a n/a
2017-10-25 2017-09-30 13F MAIN STREET CAPITAL CALL Call 9 200.00 0 n/a n/a n/a
2017-07-12 2017-06-30 13F MAIN STREET CAPITAL CALL Call 3 -87.50 0 -100.00 n/a n/a n/a
2017-04-21 2017-03-31 13F MAIN STREET CAPITAL CALL Call 24 700.00 3 200.00 n/a n/a n/a
2017-01-11 2016-12-31 13F MAIN STREET CAPITAL CALL Call 3 -81.25 1 n/a n/a n/a
2016-10-07 2016-09-30 13F MAIN STREET CAPITAL CALL Call 16 -71.93 0 -100.00 n/a n/a n/a
2016-07-18 2016-06-30 13F MAIN STREET CAPITAL CALL Call 57 26.67 13 550.00 n/a n/a n/a
2016-04-14 2016-03-31 13F MAIN STREET CAPITAL CALL Call 45 350.00 2 -84.62 n/a n/a n/a
2016-01-20 2015-12-31 13F MAIN STREET CAPITAL CALL Call 10 -28.57 0 -100.00 n/a n/a n/a
2015-10-08 2015-09-30 13F MAIN STREET CAPITAL CALL Call 14 366.67 0 n/a n/a n/a
2015-07-08 2015-06-30 13F MAIN STREET CAPITAL CALL Call 3 -57.14 0 n/a n/a n/a
2015-04-21 2015-03-31 13F MAIN STREET CAPITAL CALL Call 7 -50.00 0 -100.00 n/a n/a n/a
2015-03-04 2014-12-31 13F MAIN STREET CAPITAL CALL Call 14 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 MAIN STR CAP PUT Put 25,400 -50.78 1,345 -56.84 n/a n/a n/a
2026-02-11 2025-12-31 13F MAIN STR CAP PUT Put 51,600 -28.03 3,116 77,800.00 n/a n/a n/a
2025-11-12 2025-09-30 13F MAIN STR CAP PUT Put 71,700 71.53 5 100.00 n/a n/a n/a
2025-08-05 2025-06-30 13F MAIN STR CAP PUT Put 41,800 -16.73 2 0.00 n/a n/a n/a
2025-05-12 2025-03-31 13F MAIN STR CAP PUT Put 50,200 1,294.44 3 n/a n/a n/a
2025-02-11 2024-12-31 13F MAIN STR CAP PUT Put 3,600 12.50 0 n/a n/a n/a
2024-11-08 2024-09-30 13F MAIN STR CAP PUT Put 3,200 -8.57 0 n/a n/a n/a
2024-07-25 2024-06-30 13F MAIN STR CAP PUT Put 3,500 775.00 0 n/a n/a n/a
2024-04-25 2024-03-31 13F MAIN STR CAP PUT Put 400 -87.88 0 n/a n/a n/a
2024-02-02 2023-12-31 13F MAIN STR CAP PUT Put 3,300 10.00 0 n/a n/a n/a
2023-11-01 2023-09-30 13F MAIN STR CAP PUT Put 3,000 -62.50 0 n/a n/a n/a
2023-08-04 2023-06-30 13F MAIN STR CAP PUT Put 8,000 -40.74 0 n/a n/a n/a
2023-04-27 2023-03-31 13F MAIN STR CAP PUT Put 13,500 321.88 1 n/a n/a n/a
2023-02-02 2022-12-31 13F MAIN STR CAP PUT Put 3,200 -88.01 0 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F MAIN STR CAP PUT Put 26,700 456.25 898 388.04 n/a n/a n/a
2022-08-03 2022-06-30 13F MAIN STR CAP PUT Put 4,800 -84.11 184 -85.70 n/a n/a n/a
2022-05-02 2022-03-31 13F MAIN STR CAP PUT Put 30,200 127.07 1,287 115.94 n/a n/a n/a
2022-02-23 2021-12-31 13F/A MAIN STR CAP PUT Put 13,300 7.26 596 16.86 n/a n/a n/a
2022-02-04 2021-12-31 13F MAIN STR CAP PUT Put 12,400 510 n/a n/a n/a
2021-10-28 2021-09-30 13F MAIN STR CAP PUT Put 12,400 0.81 510 0.99 n/a n/a n/a
2021-08-12 2021-06-30 13F MAIN STR CAP PUT Put 12,300 4,041.41 505 -56.54 n/a n/a n/a
2021-04-26 2021-03-31 13F MAIN STR CAP PUT Put 297 38.79 1,162 68.41 n/a n/a n/a
2021-02-02 2020-12-31 13F MAIN STR CAP PUT Put 214 -19.25 690 -11.88 n/a n/a n/a
2020-10-14 2020-09-30 13F MAIN STR CAP PUT Put 265 10.42 783 4.82 n/a n/a n/a
2020-07-13 2020-06-30 13F MAIN STR CAP PUT Put 240 18.23 747 79.57 n/a n/a n/a
2020-04-29 2020-03-31 13F MAIN STR CAP PUT Put 203 448.65 416 161.64 n/a n/a n/a
2020-02-05 2019-12-31 13F MAIN STREET CAPITAL PUT Put 37 1,133.33 159 1,225.00 n/a n/a n/a
2019-10-15 2019-09-30 13F MAIN STREET CAPITAL PUT Put 3 -81.25 12 -81.54 n/a n/a n/a
2019-07-26 2019-06-30 13F MAIN STREET CAPITAL PUT Put 16 -42.86 65 -37.50 n/a n/a n/a
2019-04-18 2019-03-31 13F MAIN STREET CAPITAL PUT Put 28 -72.82 104 -70.11 n/a n/a n/a
2019-01-16 2018-12-31 13F MAIN STREET CAPITAL PUT Put 103 442.11 348 376.71 n/a n/a n/a
2018-10-23 2018-09-30 13F MAIN STREET CAPITAL PUT Put 19 1,800.00 73 2,333.33 n/a n/a n/a
2018-07-30 2018-06-30 13F MAIN STREET CAPITAL PUT Put 1 -99.53 3 -95.38 n/a n/a n/a
2018-04-26 2018-03-31 13F MAIN STREET CAPITAL PUT Put 213 1,021.05 65 6,400.00 n/a n/a n/a
2018-01-10 2017-12-31 13F MAIN STREET CAPITAL PUT Put 19 -77.38 1 -75.00 n/a n/a n/a
2017-10-25 2017-09-30 13F MAIN STREET CAPITAL PUT Put 84 250.00 4 300.00 n/a n/a n/a
2017-07-12 2017-06-30 13F MAIN STREET CAPITAL PUT Put 24 -60.66 0 -100.00 n/a n/a n/a
2017-04-21 2017-03-31 13F MAIN STREET CAPITAL PUT Put 61 -18.67 1 -87.50 n/a n/a n/a
2017-01-11 2016-12-31 13F MAIN STREET CAPITAL PUT Put 75 97.37 8 14.29 n/a n/a n/a
2016-10-07 2016-09-30 13F MAIN STREET CAPITAL PUT Put 38 -78.77 7 -22.22 n/a n/a n/a
2016-07-18 2016-06-30 13F MAIN STREET CAPITAL PUT Put 179 77.23 9 80.00 n/a n/a n/a
2016-04-14 2016-03-31 13F MAIN STREET CAPITAL PUT Put 101 431.58 5 -44.44 n/a n/a n/a
2016-01-20 2015-12-31 13F MAIN STREET CAPITAL PUT Put 19 280.00 0 -100.00 n/a n/a n/a
2015-10-08 2015-09-30 13F MAIN STREET CAPITAL PUT Put 5 0.00 1 n/a n/a n/a
2015-07-08 2015-06-30 13F MAIN STREET CAPITAL PUT Put 5 -28.57 0 -100.00 n/a n/a n/a
2015-04-21 2015-03-31 13F MAIN STREET CAPITAL PUT Put 7 133.33 0 n/a n/a n/a
2015-03-04 2014-12-31 13F MAIN STREET CAPITAL PUT Put 3 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.