Plug Power shares plunged 10.69% Friday to $3.215, now 18.6% below their May 29 close, just days before a June 11 shareholder vote on adding 25 million shares to its stock plan—a move that could dilute existing investors if issued—while recent $39.2 million in tax credit sales added financial flexibility amid sector-wide selloffs and growing concerns over cash flow, capital, and market volatility.