Company: GCTS
Filing Date: 2025-05-16
Form Type: 424B5
Source: 0001104659-25-049833
Chunk: 1

Company: GCT Semiconductor Holding, Inc.
Filing Date: 2025-05-16
Form: 424B5
Chunk 1
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 of these securities nor is it required to sell any specific
number or dollar amount of securities, but has agreed to use its reasonable best efforts to arrange the sale of the Securities offered
by this prospectus supplement. We have agreed to pay the Placement Agent the Placement Agent fees set forth in the table below.

Investing in our securities involves a high degree of risk. Before
deciding whether to invest in our securities, you should review carefully the risks and uncertainties described under the heading “Risk
Factors” beginning on page S-5 of this prospectus supplement and in the documents incorporated by reference into this
prospectus supplement. This prospectus supplement should be read in conjunction with and may not be delivered or utilized without the
prospectus dated April 9, 2025.

| ​                                |     | Per Share and 
 Accompanying  
 Warrant       |        |     | Total |               |
|:---------------------------------|:----|:--------------|-------:|:----|:------|--------------:|
| Offering price                   |     | $             |   1.57 |     | $     | 11,000,000.90 |
| Placement Agent fees             |     | $             | 0.1099 |     | $     |    770,000.06 |
| Proceeds, before expenses, to us |     | $             | 1.4601 |     | $     | 10,230,000.84 |

We estimate the expenses of
this Offering, excluding Placement Agent fees, will be approximately $150,000. After deducting the fees due to the Placement Agent and
our estimated offering expenses, we expect the net proceeds from this offering to be approximately $10 million, assuming we sell the maximum
amount of Securities offered hereby and assuming no exercise of the Warrants. Delivery of the Shares of Common Stock and Warrants is expected
to be made on or about May 16, 2025, subject to customary closing conditions.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

<div align='center'>Roth Capital Partners

The date of this prospectus supplement is May 15, 2025.

TABLE OF CONTENTS</div>

Prospectus Supplement

| ABOUT THIS PROSPECTUS SUPPLEMENT                     |     | S-1