Business correspondent Christine Romans reports Wall Street is heading into what will likely be a volatile trading day on Wednesday. Global markets’ bad start to 2016 just got uglier. Asian stocks fell sharply Wednesday as oil sank below $28 a barrel to its lowest level in more than 12 years. Japan’s Nikkei nosedived 3.7%, taking it more than 20% below its recent high in June and into bear market territory. The Hang Seng in Hong Kong slumped 3.8% to a 3-year low. The crash in oil prices keeps getting worse, heightening concerns about the health of the world economy. U.S. crude oil tumbled below $28 a barrel for the first time since September 2003, hitting a low of $27.42. Investors remain jittery over the flood of supply Iran is preparing to unleash on the saturated market in the coming months after the lifting of Western sanctions. Energy stocks were among the biggest losers in Hong Kong.