Effective Friday, July 31, 2015, Nasdaq, BX and PSX have issued guidelines to provide additional clarification as to the types of trading behavior that are prohibited, such as layering and spoofing.

Business Conduct Rules are to be found in the Nasdaq Rule Book and listed are some, but not all rules, concerning manipulative trading behavior. Comparable rules are found in the BX and PHLX rulebooks. 

• Nasdaq 2010A. Standards of Commercial Honor and Principles of Trade: A member, in the conduct of its business, shall observe high standards of commercial honor and just and equitable principles of trade.
• Nasdaq 2120. Use of Manipulative, Deceptive or Other Fraudulent Devices: No member shall effect any transaction by means of any manipulative, deceptive or other fraudulent device or contrivance.
• Nasdaq 3310. Publication of Transactions and Quotations. No member shall publish or circulate, or cause to be published or circulated, any notice, circular, advertisement, newspaper article, investment service, or communication of any kind which purports to report any transaction as a purchase or sale of any security unless such member believes that such transaction was a bona fide purchase or sale of such security.
• Nasdaq 3320. Offers at Stated Prices. Prohibition on submitting bids/offers when a member is unwilling to execute at its stated price.
• Nasdaq 3351. Trading Practices
  (a) No member shall execute or cause to be executed or participate in an account for which there are executed purchases of any "NMS Stock" (as defined in SEC Rule 600(b)(42)) at successively higher prices, or sales of any such security at successively lower prices, for the purpose of creating or inducing a false, misleading or artificial appearance of activity in such security or for the purpose of unduly or improperly influencing the market price for such security or for the purpose of establishing a price which does not reflect the true state of the market in such security.
  
  

Please see attached FAQ for further details.