Recent amendments to U.S. Commodity Futures Trading Commission (CFTC) rules have required many hedge fund firms to confront the prospect of registering with the CFTC as a commodity pool operator (CPO) and/or commodity trading advisor (CTA).  Notably, the CFTC in February announced the rescission of Rule 4.13(a)(4), a CPO registration exemption that for years has allowed hedge funds to trade without limitation in CFTC-regulated “commodity interests” (i.e., futures contracts, options on futures, retail f/x transactions and, effective October 12, 2012, many types of swaps).  Going forward, most U.S. hedge fund firms that operate funds for which they cannot rely on the alternative CPO registration exemption in Rule 4.13(a)(3) – which imposes significant limits on a fund’s commodity interest trading – will have little choice but to register with the CFTC.  For firms registered as investment advisers with the U.S. Securities and Exchange Commission, many aspects of the CFTC registration process, as well as certain ongoing recordkeeping, reporting and disclosure obligations, will be familiar.  But one area where the CFTC requirements for registered CPOs and CTAs depart significantly from the norms of SEC investment adviser regulation is the general requirement that a CFTC registrant’s marketing personnel (so-called “associated persons” or APs) satisfy certain proficiency testing requirements – in general, timely passage of the “Series 3” examination.  In a guest article, Sean Finley, Jared Gianatasio and Nathan Greene summarize the scope of a CPO’s or CTA’s personnel who will be APs generally subject to the Series 3 proficiency requirement and highlight several exemptions and proficiency testing alternatives that can offer relief from that requirement.  Finley is a partner, Gianatasio is a senior associate and Greene is a partner and Co-Practice Group Leader in Shearman & Sterling LLP’s Asset Management Group.