Premarket: Global shares slide as Russia-Ukraine conflict, OPEC+ output plan push oil prices higher

Global shares sank on Monday and oil prices jumped as trade tensions and the Russian-Ukraine conflict ratcheted up geopolitical uncertainty. The future for the S&P 500 lost 0.5% while that for the Dow Jones Industrial Average gave up 0.4%. Germany's DAX retreated 0.4% to 23,891.11 and the CAC 40 in Paris declined 0.5% to 7,712.40. British FTSE 100 gained 1% to 8,778.84. In Asia, Hong Kong's Hang Seng initially plunged more than 2% as Beijing and Washington traded harsh words over trade. U.S. President Donald Trump's announcement that he will double tariffs on steel and aluminum to 50% layered on…