I'm leery of the brokers' claims that the swaps are not taxable. The brokers have a vested interest in the claim, and they are not my tax accountant, so I'm not sure I consider their opinion authoritative. The IRS definitely disagrees with them.
https://www.irs.gov/pub/irs-utl/OC-...achtransactionistaxabletobothpartiesFINAL.pdf
Of course, there isn't a record of it sent to the IRS in the form of a 1099, and the chances of an audit are low (and currently dropping), so it's "taxable" but probably not taxable unless one is overwhelmingly scrupulous about how they file taxes.
I tend to be in the "overwhelmingly scrupulous" category, but that's in part because about half of our household income historically came from sole proprietorships, and those are known to attract more IRS attention. For example, I don't claim a home office exemption, because we don't use that room "exclusively" for work, and I don't want to have to be in the position of saying we do under oath.