their own rules — rules they are bound to comply with under § 78s(g)(l) — by improperly charging PFOF fees. Thus, removal was proper because the plain language of the Exchange Act establishes that federal courts have exclusive jurisdiction over actions seeking to interpret and enforce compliance with exchange rules or the Act itself. The district court correctly determined that this case implicates a federal interest sufficiently substantial to establish federal subject matter jurisdiction. See, e.g., D’Alessio v. N.Y. Stock Exch., Inc., 258 F.3d 93, 101 (2d Cir.2001) (finding federal subject matter jurisdiction where an exchange failed to perform its statutory duty under federal law); Sparta Surgical Corp. v. Nat’l Ass’n of Sec. Dealers, Inc., 159 F.3d 1209, 1212 (9th Cir.1998) (<HOLDING>). We therefore affirm the district court’s
holding that the remedies are exclusive holding that although plaintiffs theories are posited as state law claims their viability depended on whether the sros rules were violated thereby triggering the exclusive jurisdiction provision of  78aa holding the state law claims were not preempted holding that the plaintiffs state law claims are preempted by federal law holding that exercise of jurisdiction over plaintiffs state law claims was proper on the basis of supplemental jurisdiction even though the plaintiffs had erroneously claimed diversity jurisdiction because a legitimate federal question was also presented and the state law claims formed part of the same case or controversy as the federal claim