Just this month, Meta Platforms Inc. has secured about $60 billion in capital to build data centers, part of its spending to get ahead in the artificial intelligence race. Half of that won’t show up on the social media giant’s balance sheet as debt. Meta is among firms popularizing a way for debt to sit completely off balance sheet, allowing enormous sums to be raised while limiting impact on its financial health. Morgan Stanley structured a $30 billion deal — the largest private capital transac...