The Company follows the guidance in Accounting Standards Codification (“ASC”) 820, “Fair Value Measurement” for its liabilities that are re-measured and reported at fair value at the end of each reporting period.

The fair value of the Company’s common and preferred stock warrant liabilities reflects management’s estimate of amounts that the Company would have received in connection with the sale of the assets or paid in connection with the transfer of the liabilities in an orderly transaction between market participants at the measurement date. The following fair value hierarchy is used to classify assets and liabilities based on the observable inputs and unobservable inputs used in order to value the assets and liabilities:

The Company classifies financial instruments in Level 3 of the fair value hierarchy when there is reliance on at least one significant unobservable input to the valuation model. In addition to these unobservable inputs, the valuation models for Level 3 financial instruments typically also rely on a number of inputs that are readily observable, either directly or indirectly. The Company’s assessment of a particular input to the fair value measurement requires management to make judgments and consider factors specific to the asset or liability. The fair value hierarchy requires the use of observable market data when available in determining fair value. The Company recognizes transfers between levels within the fair value hierarchy, if any, at the end of each period.

Assets and Liabilities Measured at Fair Value on a Recurring Basis

Financial Assets

The Company values its Level 1 assets, consisting of money market funds, and U.S. treasury bills and bonds, using quoted prices in active markets for identical instruments.

Financial assets whose fair values that are measured on a recurring basis using Level 2 inputs consist of commercial paper, corporate securities, and U.S. government and agency securities. The Company measures the fair values of these assets with the help of a pricing service that either provides quoted market prices in active markets for identical or similar securities or uses observable inputs for their pricing without applying significant adjustments.

Public and Private Placement Warrants

The Company assumed 1,437,499 publicly-traded warrants (“Public Warrants”) and 825,000 private placement warrants issued by NavSight (“Private Warrants” and, together with the Public Warrants, the “Warrants”) upon the Merger, all of which were issued in connection with NavSight’s initial public offering and entitled the holder to purchase one share of the Company’s Class A common stock at an exercise price of $92.00 per share. The fair value of the Public Warrants was based on the quoted market price and was classified as a Level 1 financial instrument.

In November 2022, the Company announced the commencement of an exchange offer (the "Offer") and consent solicitation relating to all holders of the Warrants to receive 0.2 shares of Class A common stock in exchange for each outstanding Warrant tendered by the holder. On December 19, 2022, a total of 2,069,561 Warrants were tendered and exchanged for 413,910 shares of Class A common stock.

Concurrently with the Offer, the Company also solicited consents from holders of the Public Warrants to amend the Warrant Agreement to permit the Company to require that each Warrant that was outstanding upon the closing of the Offer be exchanged for 0.18 shares of Class A common stock, which is a ratio 10% less than the exchange ratio applicable to the Offer (such amendment, the “Warrant Amendment”). Because consents were received from holders of more than 65% of the Company’s outstanding Public Warrants, the Warrant Amendment was approved. On December 19, 2022, the Company exercised its right to acquire and retire all remaining outstanding Public Warrants in exchange for shares of Class A common stock in accordance with the terms of the Warrant Amendment. The remaining 192,936 Public Warrants were exchanged on January 4, 2023 for 34,728 shares of the Company's Class A common stock. Following the exchange, none of the Warrants remain outstanding.

Credit Agreement Warrants

On June 13, 2022, in connection with the Blue Torch Financing Agreement, the Company issued warrants to Blue Torch, which were exercisable for an aggregate of 437,024 shares of the Company’s Class A common stock with a per share exercise price of $16.08 (the “2022 Blue Torch Warrants”). Additionally, in connection with the closing of the financing, the Company issued a warrant to Urgent Capital LLC for introducing the Company to the Lenders, which is exercisable for an aggregate of 24,834 shares of the Company's Class A common stock with a per share exercise price of $16.08 (together with the 2022 Blue Torch Warrants and the 2023 Blue Torch Warrants (as defined below), the “Credit Agreement Warrants”).

On September 27, 2023, in connection with the Waiver and Amendment, the Company and certain affiliates of Blue Torch amended and restated the 2022 Blue Torch Warrants to reduce the per share exercise price from $16.08 to $5.44. The Company also concurrently issued new warrants to those affiliates that are exercisable for an additional 597,082 shares of the Company’s Class A common stock at a per share exercise price of $5.44 (the “2023 Blue Torch Warrants").

The fair value of the Credit Agreement Warrants is estimated using the Black-Scholes model with inputs that include the Company’s Class A common stock price in an actively traded market, making this fair value classified as a Level 2 financial instrument. The other significant assumptions used in the model are the exercise price, expected term, volatility, interest rate, and expected dividend yield.

Contingent Earnout Liability

In connection with the Merger, eligible Spire equity holders are entitled to receive additional shares of the Company's Class A common stock upon the achievement of certain earnout triggering events. The estimated fair value of the contingent earnout liability is determined using a Monte Carlo simulation using a distribution of potential outcomes on a monthly basis over the earnout period, which is a period up to five years post-closing of the Merger, prioritizing the most reliable information available, making this fair value classified as a Level 3 liability.

The assumptions utilized in the calculation are based on the achievement of certain stock price milestones, including the current price of the Company’s Class A common stock, expected volatility, risk-free interest rate, expected term and expected dividend yield.

Cash and Cash Equivalents and Marketable Securities

In accordance with the Company's investment policy, investments are placed in investment grade securities with high credit quality issuers, and generally limit the amount of credit exposure to any one issuer. The Company evaluates securities for impairment at the end of each reporting period. The Company did not record any impairment charges related to its available-for-sale securities during the three and nine months ended September 30, 2023 and 2022.