This is an annoying thing to see happen. It would be lovely if the prospectuses of items like SVXY and VIXY could commit to no Unearned Business Income so that IBKR would allow them in retirement accounts. That way it would be easier to avoid needing ETN’s such as VXX.
During the morning spike, I was thinking it shouldn’t be up so much. People can buy other VIX products. Though maybe for what you mentioned (VXX in retirement accounts) that people are buying it. In any case, I guess the morning rush to buy it faded, though it’s still above NAV!