Nine months ended September 30, 2021 compared to nine months ended September 30, 2020:
Interest expense decreased by $6.0 million, or 58% from $10.3 million in the nine months ended September 30, 2020 to $4.3 million in the nine months ended September 30, 2021. The decrease was primarily due to a decreased interest rates paid during the nine months ended September 30, 2021 compared with the nine months ended September 30, 2020, as a result of the January 2021 amendment to the Company’s senior secured term loans, their subsequent repayment and the fact that the new 2026 Notes issued in September 2021 have substantially lower interest rate.
Change in fair value of earnout liability
Changes in fair value of earnout liability were $7.4 million gain and $15.4 million (loss) in the three and nine months ended September 30, 2021, respectively. During the nine months ended September 30, 2021, $25.8 million of the earnout liability was reclassified to additional paid in capital as a result of a vesting event in March 2021.
Change in fair value of private warrant liability
Changes in fair value of private warrant liability were $2.7 million gain and $17.5 million (loss) in the three and nine months ended September 30, 2021, respectively. During the three months and nine months ended September 30, 2021, $14.5 million and $31.3 million, respectively, was reclassified to additional paid in capital as a result of warrant exercises.
Gain (loss) on extinguishment of debt
Three months ended September 30, 2021 compared to three months ended September 30, 2020:
Loss on extinguishment of debt was $3.1 million and $2.5 million in the three months ended September 30, 2021 and 2020, respectively. The $3.1 million loss in the three months ended September 30, 2021 relates to the repayment of all outstanding obligations under the Runway Loan Agreement. See Note 7. The $2.5 million loss in the three months ended September 30, 2020 relates to an amendment of a legacy 2019 promissory note, which was subsequently repaid.
Nine months ended September 30, 2021 compared to nine months ended September 30, 2020:
Gain on extinguishment of debt was $5.1 million and $1.1 million in the nine months ended September 30, 2021 and 2020, respectively. The $5.1 million gain in the nine months ended September 30, 2021 consists of the $8.2 million gain on extinguishment of the Porch PPP Loan, offset by the $3.1 million loss on repayment of all outstanding obligations under the Runway Loan Agreement. The $1.1 million gain in the nine months ended September 30, 2020 relates to the net impact of extinguishments of several Company’s legacy promissory notes.
Investment income and realized gains, net of investment expenses
Investment income and realized gains, net of investment expenses was $0.2 million and $0.4 million in the three and nine months ended September 30, 2021, respectively.
Other income (expense)
Three months ended September 30, 2021 compared to three months ended September 30, 2020:
Other income, net was trivial and did not change significantly in both periods.
Nine months ended September 30, 2021 compared to nine months ended September 30, 2020:
Other expense, net was $0.2 million income in the nine months ended September 30, 2021 and $2.1 million expense in the nine months ended September 30, 2020. The $2.3 million change was primarily due to $1.2 million loss on