Interest expense decreased by $0.6 million, or 35%, for the nine months ended September 30, 2021 compared to the nine months ended September 30, 2020. The decrease was attributable primarily to the reduction in our average debt outstanding during the nine months ended September 30, 2021 as compared to the nine months ended September 30, 2020. A decrease in the weighted average interest rate, from 1.9% for the nine months ended September 30, 2020 to 1.4% for the nine months ended September 30, 2021, also contributed to the decrease in interest during the period.
Other Income (Expense), Net. Other income (expense), net decreased by $2.1 million for the three months ended September 30, 2021 compared to the three months ended September 30, 2020. The decrease was attributable primarily to a change in the amount of foreign currency gains and losses, from a gain of $1.2 million in the three months ended September 30, 2020 to a loss of $0.8 million in the three months ended September 30, 2021.
Other income (expense), net decreased by $2.0 million for the nine months ended September 30, 2021 compared to the nine months ended September 30, 2020. The decrease was attributable primarily to a change in the amount of foreign currency gains and losses, from a gain of $0.5 million in the nine months ended September 30, 2020 compared to a loss of $1.3 million in the nine months ended September 30, 2021.
Benefit for Income Taxes
| | | | | | | | | | | | | | | | | | | | | | | | |
| | Three Months Ended | | | | | | | | Nine Months Ended | | | | | | |
| | September 30, | | Change | | September 30, | | Change |
| | 2021 | | 2020 | | $ | | % | | 2021 | | 2020 | | $ | | % |
|
| | (dollars in thousands) | |
Benefit for income taxes | | $ | 8,624 | | $ | 4,061 | | $ | 4,563 | | 112 | % | | $ | 15,938 | | $ | 8,937 | | $ | 7,001 | | 78 | % |
Our benefit for income taxes was $8.6 million and $4.1 million for the three months ended September 30, 2021 and 2020, respectively. For the nine months ended September 30, 2021 and 2020, our benefit for income taxes was $15.9 million and $8.9 million, respectively. The increase in the tax benefit for the three and nine months ended September 30, 2021 as compared to the three and nine months ended September 30, 2020 primarily relates to a larger expected pre-tax loss in 2021 as compared to 2020, the release of a foreign valuation allowance, the partial release of a domestic valuation allowance, and an increase in R&D and other credits recorded in the three and nine months ended September 30, 2021. The increase in tax benefit for the nine months ended September 30, 2021 as compared to the nine months ended September 30, 2020 was partially offset by a valuation allowance recorded against our U.S. deferred tax assets during the first quarter of 2021.
Liquidity and Capital Resources
General
As of September 30, 2021, our principal sources of liquidity were cash and cash equivalents totaling $51.0 million, which were held for working capital purposes, and borrowing availability under our Revolving Credit Facility, as described below. As of September 30, 2021, our cash equivalents were comprised of money market funds. During the nine months ended September 30, 2021 and 2020, our positive cash flows from operations have enabled us to make continued investments in supporting the growth of our business. We expect that our operating cash flows, in addition to our cash and cash equivalents, will enable us to continue to make such investments in the future.
We have financed our operations primarily through cash received from operations and proceeds from our debt and equity financings. On March 30, 2020, we drew down on the remaining $97.8 million available for borrowing under our Revolving Credit Facility (described further below). Given the uncertainty in the global economy as result of the COVID-19 pandemic and out of an abundance of caution, we elected to draw down the remaining available balance to further strengthen our cash position and maintain flexibility. In February 2021, we repaid $110.0 million of the balance drawn on our Revolving Credit Facility, and in June 2021, we drew down an additional $80.0 million, which was utilized for the acquisitions of SecuredTouch and Singular Key, and for general working capital purposes. As of September 30, 2021, there was $120.0 million outstanding under our Revolving Credit Facility. We believe our existing cash and cash equivalents, our Revolving Credit Facility and