詳見Descriptions of SEC Forms（http://www.sec.gov/about/forms/secforms.htm）或SEC Form Types and Definitions（http://learn.westlawbusiness.com/support/formtypes.html）
答主為AICPA備考考生，希望為題主解答疑惑，我也藉此鞏固知識。
1. Securities Offering Registration Statement（申請上市登記表） 當一家公司發行新的證券，SEC會要求其提交申請上市登記表，內容包括： 1）Disclosures about the securities being offered for sale 2) The relationship of the new securities to the company"s other securities 3) Information similar to that filed in the annual filling 4) Audited financial statements 5) A description of business risk factors
2. Form 10-K（年報） 在美註冊上市公司每年必須提交10-K，這些表格涵蓋了財務披露，具體包括了財務數據，管理層討論與分析，以及在GAAP（Generally Accepted Accounting Principles）下編製及被審計過的財務報表。
3. Form 10-Q（季報） 在美註冊公司必須每季度提交10-Q，內容包括根據GAAP編製的未審計的財務報表，管理層討論與分析，以及根據其他特定披露要求進行的相關披露。
4. Form 11-K 該表格包括本年度員工福利計劃報告。
5. Form 20-F / Form 40-F 表格內容約等於10-K，適用於foreign private issuers，一年一file。40-F適用於在SEC註冊的加拿大公司，而20-F適用於其他在SEC註冊的非美國非加拿大公司。這些報表可以是在GAAP下編製的，也可以是在IFRS（International Financial Reporting Standards）下編製的，但如果既不是GAAP又不是IFRS，例如中國準則，那就必須調整報表了（reconciliation）。
6. Form 6-K 題主在問題中問到了此表格，此表格是適用於在SEC註冊的非美國公司，半年一file，表格內容形式上類似於10-Q（季報）。
7. Form 8-K 此表格用來披露一些主要的公司事件，例如購置或處置固定資產，財務報表的改動，會計人員變化等。
8. Form 3,4 and 5 這些表格由directors,officers和持股10%以上人員填列。
以下信息來源於搜索引擎，非專業回答，供參考： Form 20-F is an SEC filing submitted to the US Securities and Exchange Commission used by certain foreign private issuers to provide information. A form administrated by the Securities and Exchange Commission (SEC), the 6-K is a required submission for foreign private issuers of securities, pursuant to stated rules in the Securities Exchange Act of 1934. Any information that a foreign company issues to its local securities regulators, investors or stock exchange must also be submitted on the Form 6-K. As such, the 6-K is a catch-all for material information that arises in between annual and quarterly financial reports, which are also submitted to the SEC The SC 13G is a form filed with the Securities Exchange Commission (SEC) to report beneficial ownership of 5% or more of a class of securities. It is used by passive and some institutional investors.
對於國內投資者或者金融愛好者，最常見和最有意義閱讀的要數F-1，20-F，6-K了，8-K同樣值得關注。 F-1：招股書，信息詳實，乾貨滿滿； 20-F：年報，同樣很詳細，可以全面了解企業一年的各種發展和故事； 6-K：每個quarter的earnings release，簡潔明了，unaudited數據，概括季度企業表現，中間會有很多管理層的解釋（之前做審計時候，每次發了earnings release意味著又一個Q的工作接近尾聲了）； 8-K：特殊重大事項等； F-3：增發…… 以上內容全部針對中概股（非美國本土企業），做為對大家答案的補充和參考。
F-1 部分美國以外公司註冊上市聲明 Form D 規則D下的證券發行豁免註冊公告 3 首次持股聲明 4 持股變動聲明 5 持股變動年度報告 S-1 註冊上市聲明 POS AM 招股信息更正說明 13D 股東單獨或合併持有5%以上公司股份公告 144 證券擬出售報告 20-F 美國以外上市公司的年度報告或過度報告 ARS 股東年報 6-K 美國以外上市公司的臨時報告 10-Q 季報 10-K 年報 8-K 季報發布期間的重要事件或公司變化臨時報告 11-K 員工持股變動年度報告 DEF 14-A 股東委託書決議
補充一個， 14A，股東大會，看公司薪資激勵和高管信息很有用
①10-K (Annual Report) The 10-K is an annual report ?led with the SEC by a public registrant that provides a comprehensive overview of the company and its prior year performance.17 It is required to contain an exhaustive list of disclosure items including, but not limited to, a detailed business description, management discus-sion analysis (MDA),18 audited ?nancial statements19 and supplementary data, outstanding debt detail, basic shares outstanding, and stock options/warrants data. It also contains an abundance of other pertinent information about the company and its sector, such as business segment detail, customers, end markets, competition, insight into material opportunities (and challenges and risks), signi?cant recent events, and acquisitions.
②10-Q (Quarterly Report) The 10-Q is a quarterly report ?led with the SEC by a public registrant that provides an overview of the most recent quarter and year-to-date (YTD) period.20 It is less comprehensive than the 10-K, but provides ?nancial statements as well as MDA relating to the company』s ?nancial performance for the most recent quarter and YTD period versus the prior year periods.21 The 10-Q also provides the most recent share count information and may also contain the most recent stock options/warrants data. For detailed ?nancial information on a company』s ?nal quarter of the ?scal year, the banker refers to the 8-K containing the fourth quarter earnings press release that usually precedes the ?ling of the 10-K.
③8-K (Current Report) The 8-K, or current report, is ?led by a public registrant to report the occurrence of material corporate events or changes (「triggering event」) that are of importance to shareholders or security holders.22 For the purposes ofpreparing trading comps, key triggering events include, but are not limited to, earn-ings announcements, entry into a de?nitive purchase/sale agreement,23 completion of an acquisition or disposition of assets, capital markets transactions, and Regu-lation FD disclosure requirements.24 The corresponding 8-Ks for these events often contain important information necessary to calculate a company』s updated ?nancial statistics, ratios, and trading multiples that may not be re?ected in the most recent 10-K or 10-Q (see 「Adjustments for Recent Events」).
Proxy Statement A proxy statement is a document that a public company sends to its shareholders prior to a shareholder meeting containing material information regarding matters on which the shareholders are expected to vote. It is also ?led with the SEC on Schedule 14A. For the purposes of spreading trading comps, the annual proxy statement provides a basic shares outstanding count that may be more recent than that contained in the latest 10-K or 10-Q. As previously discussed, the annual proxy statement also typically contains a suggested peer group for benchmarking purposes.
