Investing Activities
Net cash used in investing activities for the six months ended June 30, 2022 was $0.1 million and consisted of acquisitions of equipment. Net cash provided by investing activities for the six months ended June 30, 2021 was $34.6 million and primarily represents net sales and maturities of marketable securities.
Financing Activities
Net cash provided by financing activities for the six months ended June 30, 2022 was $11.7 million, which consists of net proceeds of $4.1 million from the sale of preferred stock in a registered direct offering and proceeds of $12.6 million from the sale of 8,713, 125 shares of our common stock through an at-the-market, or ATM sales program, partially offset by a principal payment of short-term debt of $5.0 million. Net cash provided by financing activities for the six months ended June 30, 2021 was $7.1 million, which consists of net proceeds of $7.0 million from the sale of 127,849 shares of our common stock through an ATM sales program, and stock option proceeds of $0.1 million.
Funding Requirements and Other Liquidity Matters
We closely monitor our cash and cash equivalents balances, in an effort to ensure we have adequate liquidity to fund the operations of the Company. If the COVID-19 pandemic or other factors impact our current business plan or our ability to generate revenue from the launch of Twirla, we believe we have the ability to revise our commercial plans, including curtailing sales and marketing spending, to allow us to continue to fund our operations. In addition, on October 2, 2020 we filed a universal shelf registration statement with the SEC for the issuance of common stock, preferred stock, warrants, rights, debt securities and units up to an aggregate amount of $200.0 million (the “2020 Shelf Registration Statement”). On October 14, 2020, the 2020 Shelf Registration Statement was declared effective by the SEC. In the future, we may periodically offer one or more of these securities in amounts, at prices, and on terms to be announced when and if the securities are offered. At any time any of the securities covered by the 2020 Shelf Registration Statement are offered for sale, a prospectus supplement will be prepared and filed with the SEC containing specific information about the terms of any such offering.
On March 18, 2021, we filed a prospectus supplement to our 2020 Shelf Registration Statement registering an at-the-market offering program we entered into for the sale of up to $50.0 million of shares of our common stock. During the year ended December 31, 2021, we sold 172,879 shares of our common stock under the at-the-market program resulting in net proceeds of approximately $9.3 million.
On October 8, 2021, we filed a prospectus supplement to our 2020 Shelf Registration Statement registering a public offering of 666,666 shares of common stock sold together with warrants to purchase up to 333,333 shares of our common stock at a combined offering price of $34.00 per share of common stock and one-half of a warrant to purchase one share of common stock. The warrants have an exercise price of $340.00 per share, are exercisable immediately, and will expire five years from the date of issuance. On October 13, 2021, we completed the offering and realized proceeds of approximately $21.1 million, net of underwriting discounts, commissions and offering expenses.
On January 10, 2022, we filed a prospectus supplement to our 2020 Shelf Registration Statement registering the January 2022 ATM. During the six months ending June 30, 2022, we sold and issued 25,623 shares of common stock resulting in net proceeds of $0.3 million under the January 2022 ATM. On April, 26, 2022, we terminated the January 2022 ATM.
On March 13, 2022, we entered into the 2022 Preferred Stock Offering. The 2022 Preferred Stock Offering closed on March 14, 2022 and total net proceeds were approximately $4.1 million.
On April 27, 2022, we entered into the April 2022 ATM. Through June 30, 2022, we issued and sold a total of 8,687,502 shares of common stock under the April 2022 ATM, representing the entire capacity of the April 2022 ATM, resulting in net proceeds of approximately $12.2 million.
On July 6, 2022, we completed the Offering. H.C. Wainwright acted as the exclusive placement agent in connection with the Offering and, as compensation, received a cash fee of 7% of the aggregate procees raised in the Offering. We also issued to certain designees of H.C. Wainwright warrants to purchase up to 1,333,333 shares of