Investments (Tables)

6 Months Ended

Mar. 31, 2025

Investments, Debt and Equity Securities [Abstract]

Fair Value, Assets Measured on Recurring Basis

Investments as of March 31, 2025 and September 30, 2024 consisted of the following:

	As of March 31, 2025						As of September 30, 2024
	Principal		Amortized Cost		Fair Value		Principal		Amortized Cost		Fair Value
Senior secured	$	472,368	$	470,229	$	466,973	$	510,503	$	506,178	$	502,386
One stop	7,602,435		7,558,377		7,481,347		7,271,543		7,216,368		7,110,258
Second lien	31,454		29,829		26,912		18,430		17,125		14,054
Subordinated debt	32,447		32,149		32,361		30,410		29,943		30,175
Equity	N/A		582,036		613,627		N/A		533,299		578,538
Total	$	8,138,704	$	8,672,620	$	8,621,220	$	7,830,886	$	8,302,913	$	8,235,411

Schedules of Portfolio Composition at Amortization Cost and Fair Value

The following tables show the portfolio composition by geographic region at amortized cost and fair value as a percentage of total investments in portfolio companies. The geographic composition is determined by the location of the corporate headquarters of the portfolio company, which is not always indicative of the primary source of the portfolio company’s business.

	As of March 31, 2025				As of September 30, 2024
Amortized Cost:
United States
Mid-Atlantic	$	1,574,307	18.2	%	$	1,502,136	18.1	%
Midwest	1,395,266		16.1		1,391,538		16.8
West	1,304,254		15.0		1,133,878		13.7
Southeast	1,682,153		19.4		1,638,221		19.7
Southwest	1,086,170		12.5		1,041,814		12.5
Northeast	580,828		6.7		713,024		8.6
Canada	365,890		4.2		182,002		2.2
United Kingdom	415,328		4.8		395,769		4.8
Australia	19,996		0.2		20,909		0.2
Luxembourg	13,481		0.2		58,328		0.7
Netherlands	12,429		0.1		95,950		1.2
Finland	78,898		0.9		52,670		0.6
Sweden	34,346		0.4		33,243		0.4
Israel	17,379		0.2		855		0.0	*
Denmark	4,863		0.1		4,860		0.1
Germany	69,089		0.8		19,896		0.2
France	17,943		0.2		17,820		0.2
Total	$	8,672,620	100.0	%	$	8,302,913	100.0	%
Fair Value:
United States
Mid-Atlantic	$	1,595,299	18.5	%	$	1,506,726	18.3	%
Midwest	1,393,332		16.2		1,352,353		16.4
West	1,307,188		15.2		1,130,497		13.7
Southeast	1,643,880		19.1		1,634,599		19.8
Southwest	1,063,124		12.3		1,020,950		12.4
Northeast	583,760		6.8		713,123		8.7
Canada	356,035		4.1		178,003		2.2
United Kingdom	407,690		4.7		395,840		4.8
Australia	17,396		0.2		20,113		0.2
Luxembourg	13,356		0.1		57,439		0.7
Netherlands	12,580		0.1		89,708		1.1
Finland	82,063		1.0		56,608		0.7
Sweden	34,931		0.4		34,709		0.4
Israel	17,484		0.2		1,008		0.0	*
Denmark	4,880		0.1		4,896		0.1
Germany	70,114		0.8		20,493		0.3
France	18,108		0.2		18,346		0.2
Total	$	8,621,220	100.0	%	$	8,235,411	100.0	%

* Represents an amount less than 0.1%

The industry compositions of the portfolio at amortized cost and fair value as a percentage of total investments in portfolio companies as of March 31, 2025 and September 30, 2024 were as follows:

	As of March 31, 2025				As of September 30, 2024
Amortized Cost:
Aerospace & Defense	$	42,760	0.5	%	$	39,344	0.5	%
Air Freight & Logistics	49,859		0.6		—		—
Airlines	8,961		0.1		8,808		0.1
Auto Components	37,098		0.4		48,377		0.6
Automobiles	410,196		4.7		390,804		4.7
Banks	11,329		0.1		2,094		0.0	*
Beverages	95,209		1.1		82,478		1.0
Biotechnology	1,995		0.0	*	1,993		0.0	*
Building Products	61,642		0.7		60,815		0.7
Capital Markets	12,470		0.1		2,557		0.0	*
Chemicals	134,360		1.6		133,436		1.6
Commercial Services & Supplies	196,984		2.3		198,252		2.4
Communications Equipment	16,524		0.2		16,519		0.2
Construction & Engineering	10,680		0.1		4,042		0.1
Containers & Packaging	108,810		1.3		102,694		1.3
Diversified Consumer Services	460,248		5.3		391,054		4.7
Diversified Financial Services	87,139		1.0		90,456		1.1
Diversified Telecommunication Services	1,523		0.0	*	1,521		0.0	*
Electrical Utilities	6,266		0.1		—		—
Electrical Equipment	25,042		0.3		1,406		0.0	*
Electronic Equipment, Instruments & Components	33,541		0.4		33,600		0.4
Energy Equipment & Services	4,355		0.1		4,543		0.1
Food & Staples Retailing	22,184		0.3		21,957		0.3
Food Products	222,225		2.6		260,340		3.1
Healthcare Equipment & Supplies	307,354		3.5		270,891		3.3
Healthcare Providers & Services	617,191		7.1		559,659		6.7
Healthcare Technology	391,862		4.5		315,628		3.8
Hotels, Restaurants & Leisure	286,343		3.3		271,416		3.3
Household Products	9,326		0.1		8,636		0.1
Industrial Conglomerates	84,992		1.0		72,399		0.9
Insurance	494,924		5.7		460,242		5.5
Internet & Direct Marketing Retail	103,641		1.2		103,829		1.3
IT Services	278,422		3.2		294,569		3.5
Leisure Products	69,566		0.8		69,755		0.8
Life Sciences Tools & Services	133,575		1.5		115,691		1.4
Machinery	30,654		0.4		30,586		0.4
Marine	34,825		0.4		35,033		0.4
Media	13,765		0.2		13,883		0.2
Multiline Retail	29,021		0.3		43,416		0.5
Oil, Gas & Consumable Fuels	7,203		0.1		85,736		1.0
Paper & Forest Products	18,764		0.2		18,771		0.2
Personal Products	36,406		0.4		36,460		0.4
Pharmaceuticals	319,750		3.7		257,011		3.1
Professional Services	237,245		2.7		217,009		2.6
Real Estate Management & Development	105,965		1.2		211,484		2.6
Road & Rail	41,725		0.5		41,776		0.5
Software	2,265,925		26.1		2,229,206		26.9
Specialty Retail	517,179		6.0		476,296		5.7
Textiles, Apparel & Luxury Goods	44,255		0.5		43,892		0.5
Trading Companies & Distributors	55,657		0.6		55,166		0.7
Transportation Infrastructure	7,512		0.1		—		—
Water Utilities	68,173		0.8		67,383		0.8
Total	$	8,672,620	100.0	%	$	8,302,913	100.0	%

* Represents an amount less than 0.1%.

	As of March 31, 2025				As of September 30, 2024
Fair Value:
Aerospace & Defense	$	43,326	0.5	%	$	40,073	0.5	%
Air Freight & Logistics	50,286		0.6		—		—
Airlines	8,903		0.1		8,547		0.1
Auto Components	32,606		0.4		45,376		0.6
Automobiles	410,363		4.8		389,281		4.7
Banks	11,382		0.1		2,076		0.0	*
Beverages	89,112		1.0		76,785		0.9
Biotechnology	613		0.0	*	764		0.0	*
Building Products	60,989		0.7		59,962		0.7
Capital Markets	12,434		0.1		2,540		0.0	*
Chemicals	123,067		1.4		119,535		1.5
Commercial Services & Supplies	197,996		2.3		198,921		2.4
Communications Equipment	16,445		0.2		16,494		0.2
Construction & Engineering	10,677		0.1		4,050		0.0	*
Containers & Packaging	108,574		1.3		101,467		1.2
Diversified Consumer Services	448,378		5.2		385,797		4.7
Diversified Financial Services	87,666		1.0		90,588		1.1
Diversified Telecommunication Services	1,529		0.0	*	1,529		0.0	*
Electrical Utilities	6,276		0.1		—		—
Electrical Equipment	25,340		0.3		1,425		0.0	*
Electronic Equipment, Instruments & Components	34,192		0.4		34,420		0.4
Energy Equipment & Services	2,023		0.0	*	1,793		0.0	*
Food & Staples Retailing	22,313		0.3		22,811		0.3
Food Products	226,072		2.6		258,812		3.1
Healthcare Equipment & Supplies	309,636		3.6		264,737		3.2
Healthcare Providers & Services	606,836		7.0		545,927		6.6
Healthcare Technology	395,769		4.6		317,594		3.9
Hotels, Restaurants & Leisure	287,969		3.3		271,656		3.3
Household Products	9,323		0.1		8,636		0.1
Industrial Conglomerates	86,987		1.0		72,439		0.9
Insurance	492,626		5.7		458,447		5.6
Internet & Direct Marketing Retail	84,344		1.0		108,880		1.3
IT Services	288,685		3.4		302,581		3.7
Leisure Products	71,228		0.8		71,152		0.9
Life Sciences Tools & Services	135,984		1.6		113,608		1.4
Machinery	30,227		0.4		29,750		0.4
Marine	34,676		0.4		34,517		0.4
Media	13,591		0.2		13,717		0.2
Multiline Retail	29,560		0.3		31,866		0.4
Oil, Gas & Consumable Fuels	7,116		0.1		85,689		1.0
Paper & Forest Products	18,816		0.2		18,727		0.2
Personal Products	21,934		0.3		32,813		0.4
Pharmaceuticals	319,346		3.7		254,314		3.1
Professional Services	240,458		2.8		218,402		2.7
Real Estate Management & Development	103,560		1.2		211,343		2.6
Road & Rail	41,152		0.5		41,172		0.5
Software	2,278,146		26.4		2,229,502		27.1
Specialty Retail	509,182		5.9		473,726		5.8
Textiles, Apparel & Luxury Goods	44,458		0.5		43,633		0.5
Trading Companies & Distributors	52,856		0.6		50,288		0.6
Transportation Infrastructure	7,511		0.1		—		—
Water Utilities	68,682		0.8		67,249		0.8
Total	$	8,621,220	100.0	%	$	8,235,411	100.0	%

* Represents an amount less than 0.1%.