$ProShares Ultra VIX Short-Term Futures ETF (UVXY.US)$  if the market is going down, why isnt this going up??????

$MPLX LP (MPLX.US)$ why cant i sell my shares?

$ $1847 Holdings (EFSH.US)$ I have been trying to purchase these on limit most of the day and instead I get the error “Buy to open positions in this stock/option is currently unavailable.” I stocks being purchased and the stovk going up and down, but I cant purchase on any device.