just figured out that ALL USD markets on bter have pretty low volume .. to sell BTC you need to give away btc for 100$ below the market :\
Correct.
Guess why NuBits volume was so high this weekend?
It is because people wanted to sell their BTC on bter for USD, but couldnt due to spreads. But they COULD sell it for NuBits, because the NuBits market maker bot had hundreds of thousands of NuBits on both bid and ask at a very low spread.
So people sold their BTC for NuBits. Then later when the BTC price dropped and they wanted back in, they traded NuBits back into BTC. Hedging successful with low slippage!
(At least, this might be the reason. Its certainly a good explanation).