They are not stocks. They are ETNs from Proshares, like UVXY, VXX, etc.
They, like all Proshares ETNs/ETFs products, have decay built in, so price erodes over time. One is short S&P, one is short Dow. They are both down a lot in last year due to bull market, and have had reverse splits. They don't use shares, but "units", which they can create or destroy whenever they want. Good if you want to short market, or even better to short if you want to go long the market, as the decay works in your favor if you short them.Just like UVXY/VXX, but specific to Dow/S&P rather than VIX.
I haven't used them, but another option to play Dow/S&P.