Dow Down 500+ Points at Midday

It might be the worst day yet in an already lousy year for the stock market: The Dow was down more than 500 points shortly after noon, a fall of about 3.3%, and the Nasdaq and S&P 500 were down similar percentages. The news comes after yet another bad day for Asian stocks, with Japan's Nikkei falling into bear territory—roughly defined as 20% below a recent high, reports the Wall Street Journal. One huge, familiar factor: Oil prices continue to fall, with the price of a barrel now under $27 a barrel.

"Obviously we're in the throes of an environment where sentiment is not positive about risk assets, so it takes very little to put pressure ... pressure coming from falling oil prices continues to serve as a cues for equities to follow suit," a strategist at Janney Montgomery Scott tells CNBC. This MarketWatch piece suggests "the bear market in stocks has finally arrived" for US investors. (More Dow Jones stories.)