UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

ECO-STIM ENERGY SOLUTIONS, INC.

(Exact name of registrant as specified in its charter)

281-531-7200

(Registrant’s telephone number, including area code)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company [  ]

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. [  ]

Item 8.01. Other Events.

As previously disclosed, on March 29, 2018, Eco-Stim Energy Solutions, Inc. (the “Company”) entered into a Securities Purchase Agreement with its majority shareholder and other funds, all of which are under management by Fir Tree Partners (collectively, “Fir Tree”), pursuant to which Fir Tree agreed to purchase 10,000 shares of the Company’s Series A Convertible Preferred Stock, par value $0.001 per share (the “Series A Preferred”), at a price of $1,000 per share. An initial closing was conducted on April 2, 2018, providing for the Company’s sale and issuance of 10,000 shares of Series A Preferred, providing $10.0 million of gross proceeds to the Company.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.