Technical indicators say a bottom is forming, see the attached chart from AllAboutTrends. Fundamentals say the same: this is all about oil, and oil has already been forming a bottom. Markets should follow. Why this may be so is fascinating.
We should expect a final "flight to quality" to US assets as economies around the world slow down, the US being the last market standing. This has been occurring - you can see it in the rise of the USD and especially in flight capital from emerging markets. It should spill over into equities, but for some reason selling pressure has been much stronger since the new year.
The countervailing force appears to be Sovereign Wealth Funds (SWF), particularly from oil states. Their SWF's are rainy day funds, and the drop in oil means it is pouring. Places like Saudi Arabia and even Norway have tuned their spending and welfare to $80 oil, and are draining capital at $30. The Saudi's have had to embrace austerity, and to raise cash have even announced the extraordinary event of selling shares in their Aramco oil holdings.
Problem is, SWF's tend to invest in long-term, illiquid projects. Airports, solar farms, other infrastructure. The top of their stack are stocks and bonds, liquid assets. These they are dumping to provide funds back to their governments. They started last year, selling European stocks. This now appears to have tumbled into US equities. This should become clearer as reports come in, but the market won't wait. If oil has really found a bottom, and not a dead-cat bounce, US equities should turn, and turn rapidly.