The Supreme Court’s stunning rejuvenation of the Obamacare mandate into a new tax didn’t leak to Washington D.C. insiders — but it appears that it may have leaked to yet-unknown Wall Street investors. In a brief 10-minute period starting at 9:32 a.m., the stock value of the nation’s largest hospital chain, HCA Holdings Inc., jumped from $26.81 per share to $27.53 as bidders bought several hundred thousand shares before the court made its announcement just after 10 a.m. The bidders who snatched up shares before the announcement made a gain of roughly $2 a share once the price rose again...