Liquidity and Capital Resources
We have financed our operations primarily through cash provided by operating activities and borrowings under our Convertible Notes (defined below) and credit facilities. Our primary sources of liquidity as of June 30, 2019 consisted of $27.4 million of cash and cash equivalents, $42.8 million of marketable securities, $150.0 million available for borrowing under our Credit Facility, $12.9 million of which is reserved for our outstanding Letter of Credit Authorization agreements. As of June 30, 2019, we had $3.1 million outstanding under the Term Loan, and we had no amounts outstanding under the Revolving Line of Credit.
Our principal uses of liquidity have been to fund our operations, working capital requirements, capital expenditures and acquisitions. We expect that these requirements will be our principal needs for liquidity over the near term. Our capital expenditures in the six months ended June 30, 2019 were $73.9 million, of which $58.9 million will be reimbursed through revenue for DAS build-out projects from our telecom operators.
In February 2019, we entered into a Credit Agreement (the “Credit Agreement”) and related agreements with Bank of America, N.A. acting as agent for lenders named therein, including Bank of America, N.A., Silicon Valley Bank, Bank of the West, Zions Bancorporation, N.A. dba California Bank & Trust, and Barclays Bank PLC (the “Lenders”), for a secured credit facility in the form of a revolving line of credit up to $150.0 million (the “Revolving Line of Credit”) and a term loan of $3.5 million (the “Term Loan” and together with the Revolving Line of Credit, the “Credit Facility”). Our Credit Facility will mature on April 3, 2023. Amounts borrowed under the Revolving Line of Credit and Term Loan will bear variable interest at the greater of LIBOR plus 1.75% - 2.75% or Lender’s Prime Rate plus 0.75% - 1.75% per year and we will pay a fee of 0.25% - 0.5% per year on any unused portion of the Revolving Line of Credit.
Repayment of amounts borrowed under the Credit Facility may be accelerated in the event that we are in violation of the representation, warranties and covenants made in the Credit Agreement, including certain financial covenants set forth therein, and under other specific default events including, but not limited to, non-payment or inability to pay debt, breach of cross default provisions, insolvency provisions, and change in control. We are subject to customary covenants, including a minimum quarterly consolidated senior secured leverage ratio, a minimum quarterly consolidated total leverage ratio, a maximum quarterly consolidated fixed charge coverage ratio, and cash on hand minimums. The Credit Facility provides us with significant additional flexibility and liquidity to pursue our strategic objectives for capital expenditures and acquisitions that we may pursue from time to time.
In October 2018, we sold, through the initial purchasers, convertible senior notes (“Convertible Notes”) to qualified institutional buyers pursuant to Rule 144A of the Securities Act of 1933, as amended, for gross proceeds of $201.25 million. The Convertible Notes are senior, unsecured obligations with interest payable semi-annually in cash at a rate of 1.00% per annum on April 1st and October 1st of each year, beginning on April 1, 2019. The Convertible Notes will mature on October 1, 2023 unless they are redeemed, repurchased or converted prior to such date. Prior to April 1, 2023, the Convertible Notes are convertible at the option of holders only during certain periods and upon satisfaction of certain conditions. Thereafter, the Convertible Notes will be convertible at any time until the close of business on the second scheduled trading day immediately preceding the maturity date. Upon conversion, the Convertible Notes may be settled in shares of our common stock, cash or a combination of cash and shares of our common stock, at our election.
The Convertible Notes have an initial conversion rate of 23.6323 shares of common stock per $1,000 principal amount of the Convertible Notes, which will be subject to customary anti-dilution adjustments in certain circumstances. This represents an initial effective conversion price of approximately $42.31 per share, which represents a premium of approximately 30% to the $32.55 per share closing price of our common stock on October 2, 2018, the day we priced the offering.
We may redeem all or any portion of the Convertible Notes, at our option, on or after October 5, 2021, at a redemption price equal to 100% of the principal amount of the Convertible Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date, if the last reported sale price of our stock has been at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive