re: There are some major issues lurking in the US financial markets

Not bad thinking. The high yield spread has jumped to over 3.6% recently, but that's nothing like the 7-8% spread that would indicate true stress, so you might be getting a good deal buying cheap.

I'm looking at more vanilla stuff at the moment. I've got a little bit of SPXU, but nothing significant, as I want to wait to make sure this isn't another feint like Jan/Feb.

I did make an investment in long-dated UST, thinking that the recent spike in yields will likely subside soon (although within a larger cycle of increasing rates, of course). If we are comparing to the Jan/Feb rate-spike-plus-stock-correction, recall that the dating for back then went something like this:

Fri., 1/26 = local stock peak at 2,872.87
Fri., 2/9 (T+14 days) = local stock trough at 2,532.69 (intraday)
Wed., 2/21 (T+26 days) = local 30-yr UST yield peak (with S&P 500 reaching an intraday high at 2,747.75, recouping over 1/2 the correction losses)

Then yields generally relaxed to lower levels through mid-to-late August. I think we might see something similar over the next 2-3 weeks, where the stock market recoups about half its earlier losses as bond yields crest... especially given the recent 3Q reading of only 1.6% growth in the PCE.