* Negative euro zone inflation spurs bets on ECB bond buying* S&P 500 snaps longest losing streak in 13 months* Brent oil steadies after falling below $50 a barrel* Euro at 9-year low, some euro zone yields hit record lows(Updates market action, adds new quote)By Richard LeongNEW YORK, Jan 7 (Reuters) - U.S. and European stock prices rose on Wednesday on hopes the European Central Bank would embar