Investing activities. Our capital expenditures were $.6 million and $3.0 million in the first nine months of 2023 and 2022, respectively. During the first nine months of 2023, Valhi repaid a net $1.2 million under the promissory note ($20.7 million of gross borrowings and $21.9 million of gross repayments). During the first nine months of 2022, Valhi repaid a net $4.0 million under the promissory note ($17.1 million of gross borrowings and $21.1 million of gross repayments). See Note 10 to our Condensed Consolidated Financial Statements.
During the first nine months of 2023, we had gross purchases of U.S. treasury marketable securities aggregating $36.3 million and received gross proceeds totaling $24.0 million related to U.S. treasury bill maturities. See Note 3 to our Condensed Consolidated Financial Statements.
Financing activities. During the first nine months of 2023 and 2022, we paid aggregate quarterly dividends to CompX stockholders of $.75 per share. Additionally, in August 2022 our board of directors declared a special dividend on our Class A common stock of $1.75 per share ($21.5 million). The declaration and payment of future dividends and the amount thereof, if any, is discretionary and is dependent upon our results of operations, financial condition, cash requirements for our businesses, contractual requirements and restrictions and other factors deemed relevant by our board of directors. The amount and timing of past dividends is not necessarily indicative of the amount or timing of any future dividends which we might pay.
During the second quarter of 2022, we acquired 78,900 shares of our Class A common stock (8,900 shares from affiliates and 70,000 shares in a single market transaction) for an aggregate purchase price of $1.7 million. See Note 8 to our Condensed Consolidated Financial Statements.
Future cash requirements –
Liquidity. Our primary source of liquidity on an ongoing basis is our cash flow from operating activities, which is generally used to (i) fund capital expenditures, (ii) repay short-term or long-term indebtedness incurred primarily for capital expenditures, investment activities or reducing our outstanding stock, (iii) provide for the payment of dividends (if declared), and (iv) lend to affiliates. From time-to-time, we will incur indebtedness, primarily to fund capital expenditures or business combinations.
Periodically, we evaluate liquidity requirements, alternative uses of capital, capital needs and available resources in view of, among other things, our capital expenditure requirements, dividend policy and estimated future operating cash flows. As a result of this process, we have in the past and may in the future seek to raise additional capital, refinance or restructure indebtedness, issue additional securities, modify our dividend policy or take a combination of such steps to manage our liquidity and capital resources. In the normal course of business, we may review opportunities for acquisitions, joint ventures or other business combinations in the component products industry. In the event of any such transaction, we may consider using available cash, issuing additional equity securities or increasing our indebtedness or that of our subsidiaries.
We believe that cash generated from operations together with cash on hand, as well as our ability to obtain external financing, will be sufficient to meet our liquidity needs for working capital, capital expenditures, debt service, dividends (if declared) and any amounts we might loan from time to time under the terms of our revolving loan to Valhi discussed in Note 10 to our Condensed Consolidated Financial Statements (which loans would be solely at our discretion) for both the next 12 months and five years. To the extent that our actual operating results or other developments differ from our expectations, our liquidity could be adversely affected.
All of our $64.4 million aggregate cash, cash equivalents and marketable securities at September 30, 2023 were held in the U.S.
Capital expenditures. Firm purchase commitments for capital projects in process at September 30, 2023 totaled $.2 million. We expect our capital expenditures for 2023 will be approximately $2.0 million primarily to meet our existing customer demand and those required to properly maintain our facilities and technology infrastructure.
Stock repurchase program. At September 30, 2023, we have 523,647 shares available for repurchase under a stock repurchase program authorized by our board of directors. See Note 8 to our Condensed Consolidated Financial Statements.