Chinese tech stocks in Hong Kong are coming back with a vengeance after being abandoned as “uninvestable” three months ago. Any sell-off may open another window of opportunity as Citigroup became the latest to join the bullish camp. Funds run by the world’s biggest money managers including BlackRock, Amundi SA, JPMorgan and Fidelity have profited by picking up tech stocks in Hong Kong during the March storm and riding the rebound from there, according to fund data. Goldman Sachs said the March low likely marked the market bottom, given historical precedents. The Hang Seng Tech Index has risen 34 per…