Company: QTIWW
Filing Date: 2025-02-05
Form Type: 424B3
Source: 0001628280-25-004061
Chunk: 400

Company: QT IMAGING HOLDINGS, INC.
Filing Date: 2025-02-05
Form: 424B3
Chunk 400
---
 of the conversion right. The values of the failure to timely convert and corporate event features were deemed to be de minimis.

Significant assumptions used in the valuation of the fair value of the derivative liability as of issuance on March 4, 2024 and as of September 30, 2024 were as follows:

|                            |     |   | March 4, 2024 |      |     |   | September 30, 2024 |      |
|:---------------------------|:----|:--|--------------:|-----:|:----|:--|-------------------:|-----:|
| Fair value of common stock |     | $ |          3.53 |      |     | $ |               0.71 |      |
| Term in years              |     |   |               | 1.25 |     |   |                    | 1.23 |
| Volatility                 |     |   |         130.0 |    % |     |   |              115.0 |    % |
| Risk-free rate             |     |   |           4.9 |    % |     |   |                3.9 |    % |
| Debt discount              |     |   |          30.0 |    % |     |   |               30.0 |    % |

<div align='center'>F-49</div>

#### QT IMAGING HOLDINGS, INC.

### Notes to Condensed Consolidated Financial Statements
<div align='center'>(Unaudited)</div>

The activity for the fair value of the derivative liability during the three and nine months ended September 30, 2024 was as follows:

| Beginning balance, January 1, 2024 |     | Derivative Liability |          — |
|:-----------------------------------|:----|:---------------------|-----------:|
| Fair value at issuance             |     |                      |  5,120,900 |
| Change in fair value               |     |                      | -2,983,100 |
| Ending balance, March 31, 2024     |     |                      |  2,137,800 |
| Change in fair value               |     |                      | -1,729,700 |
| Ending balance, June 30, 2024      |     |                      |    408,100 |
| Change in fair value               |     |                      |    -87,200 |
| Ending balance, September 30