Can I ask what your objective is in doing this as opposed to simply looking for the highest yield to maturity, whether new issue or secondary market?
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If you're looking to pick up deals on secondary market "offerings", you'll likely not be successful if you're looking for folks to post them here to alert you. The best deals generally pop up in small lots and by the time anyone could come here to post about it, and you see the post, it would likely be gone. Folks watch the CD inventory for when the deals pop up (I certainly do) and if you're not ready to grab it when you see it, if it is really a bargain, it will be gone in under a minute.
As far as long term bargains, over the past few weeks, I haven't seen any secondary market bargains on longer-term CDs. Fidelity does not offer anything longer than 10 years in their secondary market inventory. Etrade offers secondary market CDs beyond 10 years, but I closed my account earlier this year, so haven't seen their inventory in some time. For 10-year secondary market at Fidelity, just in the past week the yields have poked back above 3.7% after maxing out in the 3.6% range for the past month or so.