GDS Holdings Ltd — Capital/Financing Update 2018

May 29, 2018

6-K 1 a2235882z6-k.htm 6-K QuickLinks -- Click here to rapidly navigate through this document

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SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549

FORM 6-K

Report of Foreign Private Issuer Pursuant to Rule 13a-16 or 15d-16 of the Securities Exchange Act of 1934

May 2018

Commission File Number: 001-37925

GDS Holdings Limited (Registrant's name)

2/F, Tower 2, Youyou Century Place 428 South Yanggao Road Pudong, Shanghai 200127 People's Republic of China (Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

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Form 20-F ý Form 40-F o

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Indicate by check mark if the registrant is submitting the Form 6-K on paper as permitted by Regulation S-T Rule 101(b)(1): o

Indicate by check mark if the registrant is submitting the Form 6-K on paper as permitted by Regulation S-T Rule 101(b)(7): o

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EXHIBITS

Exhibit 99.1—Press release—GDS Holdings Limited Announces Proposed Offering of US$250 Million Convertible Senior Notes

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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, thereunto duly authorized.

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/s/ WILLIAM WEI HUANG
Name:	William Wei Huang
Title:	Chief Executive Officer

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QuickLinks

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