There's a 50-page Tax Court opinion today (T.C. Memo. 2025-45, petitioners are Stevens) that mentions Bermuda options and Formosa bonds and 20% penalties for tax shelters with no economic substance.  And some of it involves artificial losses related to original issue discount.  I don't understand most of it, but it's an example of why I would stay away from any returns with seven-digit amounts related to OID.