Bloomberg The world’s most volatile new stocks are vanishing from Hong Kong after regulators tightened oversight of the city’s small-cap Growth Enterprise Market. Stocks debuting on GEM in the past 12 months rose an average 23 percent on their first day of trading, down from an eye-popping 605 percent for the year through January 2017, according to data compiled by …

Bloomberg Saudi Aramco’s chief executive said the most important tax paid by the state-owned energy giant will fluctuate with the price of oil, a significant move ahead of the company’s initial public offering this year. Adjusting the 20 percent royalty on oil revenue Aramco currently pays would help the kingdom to raise extra money if prices climb. While not unusual …

Bloomberg US natural gas soothsayers are at a stalemate. Bulls say more arctic air may vault futures above $4 for the first time since 2014. Bears see the February contract expiration and a warm spell dragging them lower. Welcome to the suddenly uncertain world of fuel trading. Eight of 17 traders and analysts surveyed by Bloomberg News predicted prices that …