jurisdiction. Income earned in other foreign jurisdictions was not material. We have not been granted any incentivized tax rates and do not operate under any tax holidays in any jurisdiction.
Liquidity and Capital Resources
As of March 31, 2022, we had $444.0 million in cash, cash equivalents and short-term marketable securities, an decrease of approximately $86.4 million from $530.4 million as of December 31, 2021. As of March 31, 2022, we had working capital, defined as current assets less current liabilities, of $523.3 million, a decrease of approximately $91.2 million from $614.5 million as of December 31, 2021.
We have a Credit Agreement with Wells Fargo Bank, National Association (the "Credit Agreement") that provides us with a $75.0 million revolving line of credit to use for general corporate purposes with a $20.0 million sub-limit for the issuance of standby and trade letters of credit. The Credit Agreement was amended on June 7, 2021, to provide an alternate borrowing rate as a replacement for LIBOR and extend the termination date from April 30, 2022, to June 7, 2026, with all other terms remaining the same. Our ability to borrow under the revolving line of credit is conditioned upon our compliance with specified covenants, including reporting and financial covenants, primarily a minimum liquidity measure and a debt to earnings ratio, with which we are currently in compliance. The Credit Agreement terminates on June 7, 2026; all advances under the revolving line of credit will become due on such date, or earlier in the event of a default. No advances were outstanding under the agreement as of March 31, 2022.
Cash From Operating Activities
Operating activities generated $74.6 million of cash in the three months ended March 31, 2022. Net income for this period was $46.2 million; we also incurred non-cash stock-based compensation expense, depreciation and intangibles amortization of $9.0 million, $8.4 million and $0.7 million, respectively. Sources of cash also included a $10.7 million decrease in accounts receivable due to timing of collections, a $3.4 million increase in taxes payable and accrued liabilities and a $1.6 million decrease in prepaid expenses and other assets. These sources of cash were partially offset by a $3.8 million increase in inventories, a $1.7 million decrease in accounts payable (excluding payables related to property and equipment).
Operating activities generated $58.1 million of cash in the three months ended March 31, 2021. Net income for this period was $39.8 million; we also incurred non-cash stock-based compensation expense, depreciation, deferred income taxes and intangibles amortization of $8.5 million, $7.5 million, $1.4 million and $1.0 million, respectively. Sources of cash also included an $12.4 million decrease in inventory reflecting strong demand for the period and a $3.3 million increase in accounts payable (excluding payables related to property and equipment) due to the timing of payments. These sources of cash were partially offset by $6.3 million decrease in taxes payable and accrued liabilities, $6.3 million increase in accounts receivable due to increased customer shipments, and a $3.3 million increase in prepaid expense and other assets, primarily due to prepaid insurances and income taxes.
Cash From Investing Activities
Our investing activities in the three months ended March 31, 2022, generated $80.2 million of cash, primarily consisting of $93.7 million from sales and maturities of marketable securities, net of purchases, offset by $14.7 million for purchases of property and equipment, primarily production-related machinery and equipment, partially offset by proceeds of $1.2 million from the sale of an office building.
Our investing activities provided $30.5 million of cash in the three months ended March 31, 2021, primarily consisting of $41.5 million from sales and maturities of marketable securities, net of purchases, offset by $11.1 million for purchases of property and equipment, primarily production-related machinery and equipment as well as construction of a new office building in Switzerland.
Cash From Financing Activities
Our financing activities in the three months ended March 31, 2022, resulted in a $142.3 million net use of cash, consisting of $134.7 million for the repurchase of our common stock and $10.7 million for the payment of dividends to stockholders, partially offset by $3.1 million from the issuance of common stock from the exercise of employee stock options and the issuance of shares through our employee stock purchase plan.