BCSF · Bain Capital Specialty Finance, Inc.

These shares were acquired in multiple transactions at prices ranging from $12.51 to $12.53, inclusive. The purchase price reported above reflects the weighted average purchase price. The reporting person hereby undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer, full information regarding the number of shares purchased at each separate price.

These shares were acquired in multiple transactions at prices ranging from $12.19 to $12.62, inclusive. The purchase price reported above reflects the weighted average purchase price. The reporting person hereby undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer, full information regarding the number of shares purchased at each separate price.

The reporting person's allocation was confirmed by the broker on June 23, 2020.

Reflects additional shares of Common Stock acquired by the reporting person in connection with the Issuer's rights offering pursuant to the over-subscription privilege.

Reflects additional shares of Common Stock acquired by the reporting person in connection with the Issuer's rights offering pursuant to the over-subscription privilege.

Reflects additional shares of Common Stock acquired by Bain Capital Distressed and Special Situations 2016 (F), L.P. ("F Holdings") and Bain Capital Credit Holdings (MRF), L.P. ("MRF Holdings") in connection with the Issuer's rights offering pursuant to the over-subscription privilege.

Following the transactions described herein, shares of Common Stock are directly held by the following entities: (a) 9,914,820.48 by F Holdings, whose general partner is Bain Capital Distressed and Special Situations 2016 Investors (F), L.P. ("F Holdings GP"), and (b) 1,907,612.19 by MRF Holdings and together with F Holdings, the "Funds"), whose general partner is Bain Capital Credit Holdings Investors (MRF), LP ("MRF Holdings GP"). Bain Capital Credit Member, LLC ("BCCM") is the general partner of F Holdings GP and MRF Holdings GP.

BCCM may be deemed to share beneficial ownership of all 11,822,432.67 shares of Common Stock held of record by the Funds, but disclaims beneficial ownership of such shares, except to the extent of its respective pecuniary interest therein.

On June 5, 2020, the reporting person exercised in full his primary subscription rights (every 4 subscription rights entitling him to purchase 1 share of Common Stock), which were issued to holders of Common Stock on the May 13, 2020 record date for the rights offering.

On June 5, 2020, the reporting person exercised in full his primary subscription rights (every 4 subscription rights entitling him to purchase 1 share of Common Stock), which were issued to holders of Common Stock on the May 13, 2020 record date for the rights offering.

Pursuant to the rights offering, the reporting person has also exercised his over-subscription privilege and may acquire additional shares of Common Stock pursuant thereto. Any such additional shares (once determined) will be reported on a subsequent Form 4.

Updated to reflect that subscription rights were disposed of as a result of the exercise rather than acquired, as incorrectly reflected in the Form 4 filed on June 8, 2020.

On June 5, 2020, the reporting person exercised in full his primary subscription rights (every 4 subscription rights entitling him to purchase 1 share of Common Stock), which were issued to holders of Common Stock on the May 13, 2020 record date for the rights offering.

Pursuant to the rights offering, the reporting person has also exercised his over-subscription privilege and may acquire additional shares of Common Stock pursuant thereto. Any such additional shares (once determined) will be reported on a subsequent Form 4.

On June 5, 2020, the reporting person exercised in full his primary subscription rights (every 4 subscription rights entitling him to purchase 1 share of Common Stock), which were issued to holders of Common Stock on the May 13, 2020 record date for the rights offering.

Pursuant to the rights offering, the reporting person has also exercised his over-subscription privilege and may acquire additional shares of Common Stock pursuant thereto. Any such additional shares (once determined) will be reported on a subsequent Form 4.

On June 5, 2020, the reporting person exercised in full her primary subscription rights (every 4 subscription rights entitling him to purchase 1 share of Common Stock), which were issued to holders of Common Stock on the May 13, 2020 record date for the rights offering.

On June 5, 2020, Bain Capital Distressed and Special Situations 2016 (F), L.P. ("F Holdings") and Bain Capital Credit Holdings (MRF), L.P. ("MRF Holdings") each exercised in full its primary subscription rights (every 4 subscription rights entitling it to purchase 1 share of Common Stock), which were issued to holders of Common Stock on the May 13, 2020 record date for the rights offering.

Pursuant to the rights offering, each of F Holdings and MRF Holdings has also exercised its over-subscription privilege and may acquire additional shares of Common Stock pursuant thereto. Any such additional shares (once determined) will be reported on a subsequent Form 4.

Following the transactions described herein, shares of Common Stock are directly held by the following entities: (a) 9,116,331.48 by F Holdings, whose general partner is Bain Capital Distressed and Special Situations 2016 Investors (F), L.P. ("F Holdings GP"), and (b) 1,753,983,19 by MRF Holdings and together with F Holdings, the "Funds"), whose general partner is Bain Capital Credit Holdings Investors (MRF), LP ("MRF Holdings GP"). Bain Capital Credit Member, LLC ("BCCM") is the general partner of F Holdings GP and MRF Holdings GP.

BCCM may be deemed to share beneficial ownership of all 10,870,314.67 shares of Common Stock held of record by the Funds, but disclaims beneficial ownership of such shares, except to the extent of its respective pecuniary interest therein.

On June 5, 2020, the reporting person exercised in full her primary subscription rights (every 4 subscription rights entitling him to purchase 1 share of Common Stock), which were issued to holders of Common Stock on the May 13, 2020 record date for the rights offering.

Pursuant to the rights offering, the reporting person has also exercised her over-subscription privilege and may acquire additional shares of Common Stock pursuant thereto. Any such additional shares (once determined) will be reported on a subsequent Form 4.

On June 5, 2020, the reporting person exercised in full his primary subscription rights (every 4 subscription rights entitling him to purchase 1 share of Common Stock), which were issued to holders of Common Stock on the May 13, 2020 record date for the rights offering.

Pursuant to the rights offering, the reporting person has also exercised his over-subscription privilege and may acquire additional shares of Common Stock pursuant thereto. Any such additional shares (once determined) will be reported on a subsequent Form 4.

Prior to the transaction, the reporting person held 15,699.19 shares of Common Stock. The Form 4 filed by the reporting person on March 2, 2020 erroneously reflected that the reporting person held 16,590.19 shares of Common Stock.

Following the transactions described herein, shares of Common Stock are directly held by the following entities: (a) 9,116,331.48 by F Holdings, whose general partner is Bain Capital Distressed and Special Situations 2016 Investors (F), L.P. ("F Holdings GP"), and (b) 1,753,983,19 by MRF Holdings and together with F Holdings, the "Funds"), whose general partner is Bain Capital Credit Holdings Investors (MRF), LP ("MRF Holdings GP"). Bain Capital Credit Member, LLC ("BCCM") is the general partner of F Holdings GP and MRF Holdings GP.

BCCM may be deemed to share beneficial ownership of all 10,870,314.67 shares of Common Stock held of record by the Funds, but disclaims beneficial ownership of such shares, except to the extent of its respective pecuniary interest therein.

On June 5, 2020, the reporting person exercised in full his primary subscription rights (every 4 subscription rights entitling him to purchase 1 share of Common Stock), which were issued to holders of Common Stock on the May 13, 2020 record date for the rights offering.

Pursuant to the rights offering, the reporting person has also exercised his over-subscription privilege and may acquire additional shares of Common Stock pursuant thereto. Any such additional shares (once determined) will be reported on a subsequent Form 4.

These shares were acquired in multiple transactions at prices ranging from $14.33 to $15.00, inclusive. The purchase price reported above reflects the weighted average purchase price. The reporting person hereby undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer, full information regarding the number of shares purchased at each separate price.

These shares were acquired in multiple transactions at prices ranging from $16.65 to $16.70, inclusive. The purchase price reported above reflects the weighted average purchase price. The reporting person hereby undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer, full information regarding the number of shares purchased at each separate price.

These shares were acquired in multiple transactions at prices ranging from $16.65 to $16.70, inclusive. The purchase price reported above reflects the weighted average purchase price. The reporting person hereby undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer, full information regarding the number of shares purchased at each separate price.

These shares were acquired in multiple transactions at prices ranging from $17.04 to $17.26, inclusive. The purchase price reported above reflects the weighted average purchase price. The reporting person hereby undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer, full information regarding the number of shares purchased at each separate price.

These shares were acquired in multiple transactions at prices ranging from $17.02 to $17.29, inclusive. The purchase price reported above reflects the weighted average purchase price. The reporting person hereby undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer, full information regarding the number of shares purchased at each separate price.

These shares were acquired in multiple transactions at prices ranging from $17.05 to $17.26, inclusive. The purchase price reported above reflects the weighted average purchase price. The reporting person hereby undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer, full information regarding the number of shares purchased at each separate price.