increase in incentive fees, management fees, and interest expense due to an increase in leverage utilization. Operating expenses per share for the six months ended June 30, 2021 and 2020 were $0.39 per share and $0.34 per share, respectively.
Incentive Fees
Incentive fees for the six months ended June 30, 2021 and 2020 were $3,812,007 and $3,220,976, respectively, incurred primarily due to net investment income. Incentive fees increased for the three months ended June 30, 2021 from the six months ended June 30, 2020 primarily due to an increase in net investment income arising from prepayments. $2,968,870 of the incentive fees for the six months ended June 30, 2021 were earned, payable in cash, and included under Accrued incentive fees on the Statement of Assets and Liabilities as of June 30, 2021. $843,137 of the incentive fees for the six months ended June 30, 2021 were deferred and accrued, and included in Accrued incentive fees on the Statement of Assets and Liabilities as of June 30, 2021. $2,532,754 of the incentive fees for the six months ended June 30, 2020 were earned, payable in cash, and included under Accrued incentive fees on the Statement of Assets and Liabilities as of June 30, 2020. $688,222 of the incentive fees for the six months ended June 30, 2020 were deferred and accrued, and included under Accrued incentive fees on the Statement of Assets and Liabilities as of June 30, 2020. Incentive fees related to PIK or deferred interest are accrued and payment is deferred until such interest is collected in cash. Incentive fees per share for the six months ended June 30, 2021 and June 30, 2020 were $0.12 and $0.12 per share, respectively.
Net Investment Income
Net investment income for the six months ended June 30, 2021 and 2020 was $22,822,211 and $17,517,428, respectively. Net investment income increased for the six months ended June 30, 2021 from the six months ended June 30, 2020, primarily due to an increase in interest income resulting from an increase in the size of the investment portfolio and an increase in prepayments. Net investment income per share for the six months ended June 30, 2021 and 2020 was $0.71 per share and $0.67 per share, respectively.
Net Realized (Loss) on Investments
The net realized loss on investments of $4,795,077 for the six months ended June 30, 2021 was primarily due to the loss on a portion of our investment in the preferred stock of CareCloud, Inc. The net realized loss on investments of $6,513,408 for the six months ended June 30, 2020 was primarily due to the loss on our senior secured loan to Aginity, Inc.
Net Change in Unrealized Appreciation (Depreciation) on Investments
Net change in unrealized depreciation on investments of $1,944,463 for the six months ended June 30, 2021 was primarily due to decreases in the fair value of our our senior secured loans to Pivot3 Holdings, Inc. and our investment in the preferred stock of Pivot3 Holdings, Inc. This was partially offset by an increase in the fair value of our investment in the common stock of Ouster, Inc. The net change in unrealized appreciation on investments of $4,317,513 for the six months ended June 30, 2020 was primarily due to increases in the fair value of our preferred stock and warrants in MTBC, Inc., and our common stock in Hercules Capital, Inc.
Net Increase in Net Assets Resulting from Operations
We had a net increase in net assets resulting from operations of $16,082,671 for the six months ended June 30, 2021, as compared to a net increase in net assets resulting from operations of $15,321,533 for the six months ended June 30, 2020. The net increase in net assets resulting from operations for the six months ended June 30, 2021 from the six months ended June 30, 2020 was primarily due to an increase in interest income resulting from an increase in the size of the investment portfolio and an increase in prepayments.
Financial Condition, Liquidity and Capital Resources
We generate cash primarily from the net proceeds of the offering of our securities and cash flows from our operations, including investment sales and repayments as well as income earned on investments and cash equivalents. We may also fund a portion of our investments through borrowings under the Credit Facilities (discussed below). We expect that we may also generate cash from any financing arrangements we may enter into in the future and any future offerings of our equity or debt securities. We may fund a portion of our investments through borrowings from banks and issuances of senior securities, which may be secured or unsecured, through