UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 Form 10-K (Mark One) ࠚ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended September 30, 2017 or □ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 814-00794 GOLUB CAPITAL BDC, INC. (Exact Name of Registrant as Specified in its Charter) Delaware 27-2326940 (State or Other Jurisdiction of (I.R.S. Employer Incorporation or Organization) Identification No.) 666 Fifth Avenue, 18th Floor, New York, NY 10103 (Address of Principal Executive Offices) (Zip Code) (212) 750-6060 (Registrant’s Telephone Number, Including Area Code) Securities registered pursuant to Section 12(b) of the Act: Title of Each Class Name of Each Exchange on Which Registered Common Stock, par value $0.001 per share The NASDAQ Stock Market LLC Securities registered pursuant to Section 12(g) of the Act: None Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes Ⅺ No ࠚ Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act. Yes Ⅺ No ࠚ Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ࠚ No Ⅺ Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). Yes Ⅺ No Ⅺ Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of the registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K. ࠚ Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer or a smaller reporting company. See definitions of ‘‘large accelerated filer’’, ‘‘accelerated filer’’ and ‘‘smaller reporting company’’ in Rule 12b-2 of the Exchange Act. (Check one): Large accelerated filer ࠚ Accelerated filer □ Non-accelerated filer □ (Do not check if a smaller reporting company) Smaller reporting company □ Emerging growth company □ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. □ Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Securities Exchange Act of 1934). Yes Ⅺ No ࠚ The aggregate market value of common stock held by non-affiliates of the registrant on March 31, 2017 based on the closing price on that date of $19.88 on the Nasdaq Global Select Market was approximately $1,135.2 million. For the purposes of calculating this amount only, all directors and executive officers of the registrant have been treated as affiliates. There were 59,577,293 shares of the registrant’s common stock outstanding as of November 20, 2017. DOCUMENTS INCORPORATED BY REFERENCE Portions of the registrant’s proxy statement to be filed with the Securities and Exchange Commission pursuant to Regulation 14A in connection with the registrant’s 2018 Annual Meeting of Stockholders, which will be filed subsequent to the date hereof, are incorporated by reference into Part III of this Form 10-K. Such proxy statement will be filed with the Securities and Exchange Commission not later than 120 days following the end of the registrant’s fiscal year ended September 30, 2017. Part I. Item 1. Business ...................................................... 3 Item 1A. Risk Factors .................................................... 30 Item 1B. Unresolved Staff Comments ......................................... 59 Item 2. Properties ..................................................... 59 Item 3. Legal Proceedings ................................................ 59 Item 4. Mine Safety Disclosures ............................................ 59 Part II. Item 5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities ....................................... 60 Item 6. Selected Consolidated Financial Data ................................... 62 Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations ..................................................... 63 Item 7A. Quantitative and Qualitative Disclosures about Market Risk ................... 91 Item 8. Consolidated Financial Statements and Supplementary Data ................... 92 Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure ..................................................... 178 Item 9A. Controls and Procedures ............................................ 178 Item 9B. Other Information ................................................ 178 Part III. Item 10. Directors, Executive Officers and Corporate Governance ...................... 179 Item 11. Executive Compensation ........................................... 179 Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters .............................................. 179 Item 13. Certain Relationships and Related Transactions, and Director Independence ......... 179 Item 14. Principal Accountant Fees and Services ................................. 179 Part IV. Item 15. Exhibits and Financial Statement Schedules .............................. 180 Signatures ..................................................... 183 i PART I In this annual report on Form 10-K, except as otherwise indicated, the terms: • ‘‘we,’’ ‘‘us,’’ ‘‘our’’ and ‘‘Golub Capital BDC’’ refer to Golub Capital BDC, Inc., a Delaware corporation, and its consolidated subsidiaries; • ‘‘Holdings’’ refers to Golub Capital BDC 2010-1 Holdings LLC, a Delaware limited liability company, or LLC, our direct subsidiary; • ‘‘2010 Issuer’’ refers to Golub Capital BDC 2010-1 LLC, a Delaware LLC, our indirect subsidiary; • ‘‘2014 Issuer’’ refers to Golub Capital BDC CLO 2014 LLC, a Delaware LLC, our direct subsidiary; • ‘‘Controlling Class’’ refers to the most senior class of notes then outstanding of the 2010 Issuer or the 2014 Issuer, as applicable; • ‘‘2010 Debt Securitization’’ refers to the $350.0 million term debt securitization that we completed on July 16, 2010 as most recently amended on October 20, 2016, in which the 2010 Issuer issued an aggregate of $350.0 million of notes, or the ‘‘2010 Notes,’’ including $205.0 million of Class A-Refi 2010 Notes, which bear interest at a rate of three-month London Interbank Offered Rate, or LIBOR, plus 1.90%, $10.0 million of Class B-Refi 2010 Notes, which bear interest at a rate of three-month LIBOR plus 2.40% and $135.0 million face amount of Subordinated 2010 Notes that do not bear interest; • ‘‘2014 Debt Securitization’’ refers to the $402.6 million term debt securitization that we completed on June 5, 2014, in which the 2014 Issuer issued an aggregate of $402.6 million of notes, or the ‘‘2014 Notes,’’ including $191.0 million of Class A-1 2014 Notes, which bear interest at a rate of three-month LIBOR plus 1.75%, $20.0 million of Class A-2 2014 Notes, which bore interest at a rate of three-month LIBOR plus 1.45% through December 4, 2015 and bear interest at three-month LIBOR plus 1.95% thereafter, $35.0 million of Class B 2014 Notes, which bear interest at a rate of three-month LIBOR plus 2.50%, $37.5 million of Class C 2014 Notes, which bear interest at a rate of three-month LIBOR plus 3.50%, and $119.1 million of LLC equity interests that do not bear interest; • ‘‘Funding’’ refers to Golub Capital BDC Funding, LLC, a Delaware LLC, our direct subsidiary; • ‘‘Credit Facility’’ refers to the amended and restated senior secured revolving credit facility that Funding originally entered into on July 21, 2011, as most recently amended on September 28, 2017, with Wells Fargo Securities, LLC, as administrative agent, and Wells Fargo Bank, N.A., as lender and collateral agent, that currently allows for borrowing up to $225 million and that bears interest at a rate of one-month LIBOR plus 2.25% per annum through the reinvestment period, which ends September 27, 2018, and bears interest at a rate of one-month LIBOR plus 2.75% for the period following the reinvestment period through the stated maturity date of September 28, 2022; • ‘‘Adviser Revolver’’ refers to the $20.0 million line of credit with GC Advisors; • ‘‘SBIC Funds’’ refers collectively to our consolidated subsidiaries, GC SBIC IV, L.P.,GC SBIC V, L.P. and GC SBIC VI, L.P.; • ‘‘SLF’’ refers to Senior Loan Fund LLC, an unconsolidated Delaware LLC, in which we co-invest with RGA Reinsurance Company, or RGA, primarily in senior secured loans. SLF is capitalized as transactions are completed and all portfolio and investment decisions in respect of SLF must be approved by representatives