2024 to July 30, 2024 (Predecessor) is related to an increase in the fair value of the April 2023 Convertible Notes, November 2023 Convertible Notes, May 2024 Convertible Notes, June 2024 Convertible Notes, and July 2024 Convertible Notes of $3.3 million, $1.7 million, $0.7 million, $0.6 million, and $0.2 million, respectively. The increases were offset by decreases in the fair value of the October 2022 Convertible notes and February 2023 Notes of $4.6 million and $39.0 thousand, respectively. The increase of $1.1 million for the three months ended September 30, 2023 (Predecessor) is due to a fair value increase of the October 2022 Convertible Notes and the April 2023 Convertible Notes of $0.9 million and $0.1 million, respectively.
The convertible notes fair value decreased $3.3 million and $2.1 million for the period from July 31, 2024 to September 30, 2024 (Successor) and from January 1, 2024 to July 30, 2024 (Predecessor), respectively, and increased $4.1 million for the nine months ended September 30, 2023 (Predecessor). The decrease of $3.3 million for the period from July 31, 2024 to September 30, 2024 (Successor) is due to a decrease in the fair value of the Convertible Securities Notes. The decrease of $2.1 million January 1, 2024 to July 30, 2024 (Predecessor) is related to decreases in the October 2022 Convertible Notes, November 2023 Convertible Notes, and February 2024 Convertible Notes of $4.3 million, $2.4 million, and $0.3 million, respectively. These decreases were offset by increases in the April 2023 Convertible Notes, May 2024 Convertible Notes, June 2024 Convertible Notes, July 2024 Convertible Notes of $3.4 million, $0.7 million, $0.6 million, and $0.2 million, respectively. The increase of $4.1 million for the nine months ended September 30, 2023 (Predecessor) is due to a fair value increase of the October 2022 Convertible Notes and the April 2023 Convertible Notes of $3.9 million and $0.2 million, respectively.
Warrant liabilities fair value adjustment
The warrant liabilities fair value decreased $5.0 million and $0.2 million for the period from July 31, 2024 to September 30, 2024 (Successor) and from July 1, 2024 to July 30, 2024 (Predecessor), respectively, and increased $22.6 thousand for the three months ended September 30, 2023 (Predecessor). The decrease of $5.0 million from July 31, 2024 to September 30, 2024 (Successor) is related to a decrease in the fair value of the PIPE Pre-funded Warrants and the Convert Warrants of $2.7 million and $2.3 million, respectively. The decrease of $0.2 million from July 1, 2024 to July 30, 2024 (Predecessor) is related to a decrease in the fair value of SVB Warrants and Series E Pre-funded Warrants of $63.3 thousand and $0.1 million, respectively. The increase of $22.6 thousand for the three months ended September 30, 2023 (Predecessor) is due to a fair value increase of the SVB Warrants.
The warrant liabilities fair value decreased $5.0 million and $0.2 million for the period from July 31, 2024 to September 30, 2024 (Successor) and from January 1, 2024 to July 30, 2024 (Predecessor), respectively, and increased $82.7 thousand for the nine months ended September 30, 2023 (Predecessor). The decrease of $5.0 million from July 31, 2024 to September 30, 2024 (Successor) is related to a decrease in the fair value of the PIPE Pre-funded Warrants and the Convert Warrants of $2.7 million and $2.3 million, respectively. The decrease of $0.2 million from January 1, 2024 to July 30, 2024 (Predecessor) is related to a decrease in the fair value of SVB Warrants and Series E Pre-funded Warrants of $77.6 thousand and $0.1 million, respectively. The increase of $82.7 thousand for the nine months ended September 30, 2023 (Predecessor) is due to a fair value increase of the SVB Warrants.
Interest expense
Interest expense was $0.4 million and $0.3 million for the period from July 31, 2024 to September 30, 2024 (Successor) and from July 1, 2024 to July 30, 2024 (Predecessor), respectively, and was $0.5 million for the three months ended September 30, 2023 (Predecessor). The increase of $0.3 million, or 52%, was related to additional interest incurred from the convertible promissory notes issued in November 2023, February 2024, May 2024, June 2024, July 2024 Notes, and the Convertible Securities Notes.
Interest expense was $0.4 million and $1.8 million for the period from July 31, 2024 to September 30, 2024 (Successor) and from January 1, 2024 to July 30, 2024 (Predecessor), respectively, and was $1.1 million for the nine months ended September 30, 2023 (Predecessor). The increase of $1.2 million, or 108% was related to additional interest incurred from the convertible promissory notes issued in April 2023, November 2023, February 2024, May 2024, June 2024, July 2024 Notes, and the Convertible Securities Notes .
Interest income
Interest income was $0.2 million and nil for the period from July 31, 2024 to September 30, 2024 (Successor) and from July 1, 2024 to July 30, 2024 (Predecessor), respectively, and was $2.0 thousand for the three months ended September 30, 2023 (Predecessor). The increase in interest income of $0.2 million is primarily due to the increase of cash balances in an asset management account.