I believe main issue is FOMO for BTC affecting altcoin and STEEM is taking big blow. However, there could be other issues such as scalability that may be hampering STEEM's value. Poloniex has disabled STEEM/SBD transfer again. There are other small issues such as big whales are power-downing big chunk of STEEM, recent voting downs of some big users by dan and ned. However, I believe when BTC settles down and as @lexiconical said BTC scaling problem comes back, STEEM will start correcting in positive ways.