Trading was halted by both the Securities and Exchange Commission and the Financial Industry Regulation Authority (FINRA), the securities industry’s self-regulatory body principally charged with monitoring activity in the opaque market. (Bloomberg) — Investors are fuming over the collapse of a $750 million mining deal that sent a tiny magnesium. when the Calgary-based penny stock surged almost 1,000 percent on a deal to sell its main assets to an unknown…