comparable sales increase of 8.7% during the 26 weeks ended July 29, 2023 was driven by a 10.1% increase in transactions and a 1.4% decrease in average ticket.
Gross profit
Gross profit increased $179.3 million or 9.6%, to $2.0 billion for the 26 weeks ended July 29, 2023, compared to $1.9 billion for the 26 weeks ended July 30, 2022. Gross profit as a percentage of net sales decreased to 39.7% for the 26 weeks ended July 29, 2023, compared to 40.3% for the 26 weeks ended July 30, 2022. The decrease in gross profit margin was primarily due to higher inventory shrink, lower merchandise margin, and higher supply chain costs, partially offset by strong growth in other revenue and leverage of store fixed costs.
Selling, general and administrative expenses
SG&A expenses increased $177.4 million or 17.1%, to $1.2 billion for the 26 weeks ended July 29, 2023, compared to $1.0 billion for the 26 weeks ended July 30, 2022. SG&A expenses as a percentage of net sales increased to 23.5% for the 26 weeks ended July 29, 2023, compared to 22.3% for the 26 weeks ended July 30, 2022, primarily due to higher corporate overhead due to strategic investments, higher store payroll and benefits, and higher marketing expenses, partially offset by leverage of incentive compensation.
Pre-opening expenses
Pre-opening expenses was $1.9 million for the 26 weeks ended July 29, 2023 compared to $4.6 million for the 26 weeks ended July 30, 2022.
Interest (income) expense, net
Net interest income was $11.8 million for the 26 weeks ended July 29, 2023 compared to net interest expense of $0.3 million for the 26 weeks ended July 30, 2022 due to higher average interest rates on cash balances. We did not have any outstanding borrowings on the credit facility as of July 29, 2023, January 28, 2023, and July 30, 2022.
Income tax expense
Income tax expense of $198.4 million for the 26 weeks ended July 29, 2023 represents an effective tax rate of 23.5%, compared to $201.8 million of income tax expense representing an effective tax rate of 24.3% for the 26 weeks ended July 30, 2022. The lower effective tax rate is primarily due to benefits from income tax accounting for stock-based compensation.
Net income
Net income was $647.2 million for the 26 weeks ended July 29, 2023 compared to $627.1 million for the 26 weeks ended July 30, 2022. The increase in net income is primarily related to the $179.3 million increase in gross profit, the $12.1 million increase in interest income, and the $3.4 million decrease in income taxes, partially offset by the $177.4 million increase in SG&A expenses.
Liquidity and capital resources
Our primary sources of liquidity are cash and cash equivalents, cash flows from operations, and borrowings under our credit facility. The most significant components of our working capital are merchandise inventories and cash and cash equivalents reduced by accounts payable, accrued liabilities and deferred revenue. As of July 29, 2023, January 28, 2023, and July 30, 2022, we had cash and cash equivalents of $388.6 million, $737.9 million, and $434.2 million, respectively.
Our primary cash needs are for rent, capital expenditures for new, remodeled, and relocated stores, increased merchandise inventories related to store expansion and new brand additions, supply chain improvements, share repurchases, and continued investment in our information technology systems.