as a percentage of income before taxes, or our annual effective tax rate, was 13.8%, 15.0%, and 12.4% in fiscal years 2014, 2013 and 2012, respectively.



Our effective tax rate on income or loss before tax for the fiscal years was lower than the United States federal statutory rate of 35% due to income or loss earned in jurisdictions, including British Virgin Islands, Hong Kong, China, Taiwan and United Kingdom, where the tax rate is lower than the United States federal statutory tax rate of 35%, favorable recognition in these fiscal years of the U.S. federal R&D tax credit and release of tax reserves as a result of the expiration of statutes of limitations in certain non-U.S. jurisdictions for which we had not previously recognized related tax benefits.



Please refer to Note 13 of the Notes to the Consolidated Financial Statements in Part IV, Item 15 of this Annual Report on Form 10-K for additional information. 



Liquidity and Capital Resources 

As of January 26, 2014, we had $4.67 billion in cash, cash equivalents and marketable securities, an increase of $943.9 million from the end of fiscal year 2013. Our portfolio of cash equivalents and marketable securities is managed on our behalf by several financial institutions which are required to follow our investment policy, which requires the purchase of high grade investment securities, the diversification of asset types and includes certain limits on our portfolio duration.



Operating activities

 

Operating activities consist primarily of net income or loss for the fiscal period, offset by the impact of non-cash expenses such as stock-based compensation and depreciation and amortization expense, and changes in operating assets and liabilities such as accounts receivable and inventories.



Cash provided by operating activities increased slightly in fiscal year 2014 compared to fiscal year 2013 primarily due to favorable changes in operating assets offset by a decrease in net income.  The favorable change in operating assets was driven mainly by a combination of a decrease in accounts receivable, resulting from strong collections and linear monthly shipments in the fourth quarter of fiscal year 2014, and a decrease in inventories.



Cash provided by operating activities decreased in fiscal year 2013 compared to fiscal year 2012 primarily due to a decrease in net income and unfavorable changes in operating assets compared to fiscal year 2012.  For example, accounts receivable increased primarily due to higher sales in the fourth quarter of fiscal year 2013 compared to the fourth quarter of fiscal year 2012 and inventory increased as a result of the production ramp of Kepler-based GPU products.



Investing activities



Investing activities consist primarily of purchases, sales and maturities of marketable securities, acquisitions of businesses and purchases of property and equipment, including leasehold improvements for our facilities and intangible assets.



Cash used in investing activities for fiscal year 2014 increased from fiscal year 2013 driven primarily by capital expenditures in fiscal year 2014 for new technology licenses and leasehold improvements at our facilities