SEC Filings

Home / Investors / Financials / SEC Filings
NASDAQ: CHKOTCPK: CHKAQ
YearTrailing 12-MonthsCalendar Year 2024Calendar Year 2023Calendar Year 2022Calendar Year 2021Calendar Year 2020Calendar Year 2019Calendar Year 2018Calendar Year 2017Calendar Year 2016Calendar Year 2015Calendar Year 2014Calendar Year 2013Calendar Year 2012Calendar Year 2011Calendar Year 2010Calendar Year 2009Calendar Year 2008Calendar Year 2007Calendar Year 2006Calendar Year 2005Calendar Year 2004Calendar Year 2003Calendar Year 2002Calendar Year 2001Calendar Year 2000Calendar Year 1999Calendar Year 1998Calendar Year 1997Calendar Year 1996Calendar Year 1995
ViewAll FilingsAnnual FilingsQuarterly FilingsCurrent FilingsRegistration StatementsSection 16Mergers & AcquisitionsProxy & Information StatementsOther
FormDescriptionDateFormat
424B2Form of prospectus filed in connection with primary offering of securities on a delayed basisDec 8, 2006Open Form of prospectus filed in connection with primary offering of securities on a delayed basis in HTML.Open Form of prospectus filed in connection with primary offering of securities on a delayed basis in DOC file.Open Form of prospectus filed in connection with primary offering of securities on a delayed basis in PDF file.Open Form of prospectus filed in connection with primary offering of securities on a delayed basis in XLS file.
424B5Form of prospectus disclosing information facts events covered in both forms 424B2 424B3Dec 7, 2006Open Form of prospectus disclosing information facts events covered in both forms 424B2 424B3 in HTML.Open Form of prospectus disclosing information facts events covered in both forms 424B2 424B3 in DOC file.Open Form of prospectus disclosing information facts events covered in both forms 424B2 424B3 in PDF file.Open Form of prospectus disclosing information facts events covered in both forms 424B2 424B3 in XLS file.
424B2Form of prospectus filed in connection with primary offering of securities on a delayed basisDec 1, 2006Open Form of prospectus filed in connection with primary offering of securities on a delayed basis in HTML.Open Form of prospectus filed in connection with primary offering of securities on a delayed basis in DOC file.Open Form of prospectus filed in connection with primary offering of securities on a delayed basis in PDF file.Open Form of prospectus filed in connection with primary offering of securities on a delayed basis in XLS file.
424B3Form of prospectus reflecting facts events constituting substantive change from last formNov 27, 2006Open Form of prospectus reflecting facts events constituting substantive change from last form in HTML.Open Form of prospectus reflecting facts events constituting substantive change from last form in DOC file.Open Form of prospectus reflecting facts events constituting substantive change from last form in PDF file.Open Form of prospectus reflecting facts events constituting substantive change from last form in XLS file.
424B3Form of prospectus reflecting facts events constituting substantive change from last formNov 16, 2006Open Form of prospectus reflecting facts events constituting substantive change from last form in HTML.Open Form of prospectus reflecting facts events constituting substantive change from last form in DOC file.Open Form of prospectus reflecting facts events constituting substantive change from last form in PDF file.Open Form of prospectus reflecting facts events constituting substantive change from last form in XLS file.
424B3Form of prospectus reflecting facts events constituting substantive change from last formAug 31, 2006Open Form of prospectus reflecting facts events constituting substantive change from last form in HTML.Open Form of prospectus reflecting facts events constituting substantive change from last form in DOC file.Open Form of prospectus reflecting facts events constituting substantive change from last form in PDF file.Open Form of prospectus reflecting facts events constituting substantive change from last form in XLS file.
424B3Form of prospectus reflecting facts events constituting substantive change from last formAug 30, 2006Open Form of prospectus reflecting facts events constituting substantive change from last form in HTML.Open Form of prospectus reflecting facts events constituting substantive change from last form in DOC file.Open Form of prospectus reflecting facts events constituting substantive change from last form in PDF file.Open Form of prospectus reflecting facts events constituting substantive change from last form in XLS file.
424B3Form of prospectus reflecting facts events constituting substantive change from last formAug 8, 2006Open Form of prospectus reflecting facts events constituting substantive change from last form in HTML.Open Form of prospectus reflecting facts events constituting substantive change from last form in DOC file.Open Form of prospectus reflecting facts events constituting substantive change from last form in PDF file.Open Form of prospectus reflecting facts events constituting substantive change from last form in XLS file.
424B3Form of prospectus reflecting facts events constituting substantive change from last formAug 3, 2006Open Form of prospectus reflecting facts events constituting substantive change from last form in HTML.Open Form of prospectus reflecting facts events constituting substantive change from last form in DOC file.Open Form of prospectus reflecting facts events constituting substantive change from last form in PDF file.Open Form of prospectus reflecting facts events constituting substantive change from last form in XLS file.
8-A12BRegistration of certain classes of securities 12(b) of the Securities Exchange ActJul 25, 2006Open Registration of certain classes of securities 12(b) of the Securities Exchange Act in HTML.Open Registration of certain classes of securities 12(b) of the Securities Exchange Act in DOC file.Open Registration of certain classes of securities 12(b) of the Securities Exchange Act in PDF file.Open Registration of certain classes of securities 12(b) of the Securities Exchange Act in XLS file.
S-8Securities offered to employees pursuant to employee benefit plansJul 21, 2006Open Securities offered to employees pursuant to employee benefit plans in HTML.Open Securities offered to employees pursuant to employee benefit plans in DOC file.Open Securities offered to employees pursuant to employee benefit plans in PDF file.Open Securities offered to employees pursuant to employee benefit plans in XLS file.
8-A12B/AAmendment to a previously filed 8-A12BJul 20, 2006Open Amendment to a previously filed 8-A12B in HTML.Open Amendment to a previously filed 8-A12B in DOC file.Open Amendment to a previously filed 8-A12B in PDF file.Open Amendment to a previously filed 8-A12B in XLS file.
8-A12B/AAmendment to a previously filed 8-A12BJul 7, 2006Open Amendment to a previously filed 8-A12B in HTML.Open Amendment to a previously filed 8-A12B in DOC file.Open Amendment to a previously filed 8-A12B in PDF file.Open Amendment to a previously filed 8-A12B in XLS file.
424B2Form of prospectus filed in connection with primary offering of securities on a delayed basisJun 29, 2006Open Form of prospectus filed in connection with primary offering of securities on a delayed basis in HTML.Open Form of prospectus filed in connection with primary offering of securities on a delayed basis in DOC file.Open Form of prospectus filed in connection with primary offering of securities on a delayed basis in PDF file.Open Form of prospectus filed in connection with primary offering of securities on a delayed basis in XLS file.
424B2Form of prospectus filed in connection with primary offering of securities on a delayed basisJun 29, 2006Open Form of prospectus filed in connection with primary offering of securities on a delayed basis in HTML.Open Form of prospectus filed in connection with primary offering of securities on a delayed basis in DOC file.Open Form of prospectus filed in connection with primary offering of securities on a delayed basis in PDF file.Open Form of prospectus filed in connection with primary offering of securities on a delayed basis in XLS file.
424B2Form of prospectus filed in connection with primary offering of securities on a delayed basisJun 29, 2006Open Form of prospectus filed in connection with primary offering of securities on a delayed basis in HTML.Open Form of prospectus filed in connection with primary offering of securities on a delayed basis in DOC file.Open Form of prospectus filed in connection with primary offering of securities on a delayed basis in PDF file.Open Form of prospectus filed in connection with primary offering of securities on a delayed basis in XLS file.
8-A12BRegistration of certain classes of securities 12(b) of the Securities Exchange ActJun 28, 2006Open Registration of certain classes of securities 12(b) of the Securities Exchange Act in HTML.Open Registration of certain classes of securities 12(b) of the Securities Exchange Act in DOC file.Open Registration of certain classes of securities 12(b) of the Securities Exchange Act in PDF file.Open Registration of certain classes of securities 12(b) of the Securities Exchange Act in XLS file.
424B5Form of prospectus disclosing information facts events covered in both forms 424B2 424B3Jun 26, 2006Open Form of prospectus disclosing information facts events covered in both forms 424B2 424B3 in HTML.Open Form of prospectus disclosing information facts events covered in both forms 424B2 424B3 in DOC file.Open Form of prospectus disclosing information facts events covered in both forms 424B2 424B3 in PDF file.Open Form of prospectus disclosing information facts events covered in both forms 424B2 424B3 in XLS file.
S-3Simplified registration formJun 26, 2006Open Simplified registration form in HTML.Open Simplified registration form in DOC file.Open Simplified registration form in PDF file.Open Simplified registration form in XLS file.
424B5Form of prospectus disclosing information facts events covered in both forms 424B2 424B3Jun 26, 2006Open Form of prospectus disclosing information facts events covered in both forms 424B2 424B3 in HTML.Open Form of prospectus disclosing information facts events covered in both forms 424B2 424B3 in DOC file.Open Form of prospectus disclosing information facts events covered in both forms 424B2 424B3 in PDF file.Open Form of prospectus disclosing information facts events covered in both forms 424B2 424B3 in XLS file.
8-A12BRegistration of certain classes of securities 12(b) of the Securities Exchange ActJun 23, 2006Open Registration of certain classes of securities 12(b) of the Securities Exchange Act in HTML.Open Registration of certain classes of securities 12(b) of the Securities Exchange Act in DOC file.Open Registration of certain classes of securities 12(b) of the Securities Exchange Act in PDF file.Open Registration of certain classes of securities 12(b) of the Securities Exchange Act in XLS file.
8-A12BRegistration of certain classes of securities 12(b) of the Securities Exchange ActJun 23, 2006Open Registration of certain classes of securities 12(b) of the Securities Exchange Act in HTML.Open Registration of certain classes of securities 12(b) of the Securities Exchange Act in DOC file.Open Registration of certain classes of securities 12(b) of the Securities Exchange Act in PDF file.Open Registration of certain classes of securities 12(b) of the Securities Exchange Act in XLS file.
8-A12BRegistration of certain classes of securities 12(b) of the Securities Exchange ActJun 23, 2006Open Registration of certain classes of securities 12(b) of the Securities Exchange Act in HTML.Open Registration of certain classes of securities 12(b) of the Securities Exchange Act in DOC file.Open Registration of certain classes of securities 12(b) of the Securities Exchange Act in PDF file.Open Registration of certain classes of securities 12(b) of the Securities Exchange Act in XLS file.
424B3Form of prospectus reflecting facts events constituting substantive change from last formJun 5, 2006Open Form of prospectus reflecting facts events constituting substantive change from last form in HTML.Open Form of prospectus reflecting facts events constituting substantive change from last form in DOC file.Open Form of prospectus reflecting facts events constituting substantive change from last form in PDF file.Open Form of prospectus reflecting facts events constituting substantive change from last form in XLS file.
424B3Form of prospectus reflecting facts events constituting substantive change from last formMay 9, 2006Open Form of prospectus reflecting facts events constituting substantive change from last form in HTML.Open Form of prospectus reflecting facts events constituting substantive change from last form in DOC file.Open Form of prospectus reflecting facts events constituting substantive change from last form in PDF file.Open Form of prospectus reflecting facts events constituting substantive change from last form in XLS file.
1-25      26-31
Subscribe to Investor Email Alerts
* Required Fields
Scroll to Top