Warning Signs Proliferate Again One of the best illustrations that we are in an unmitigated and absolutely frantic financial bubble is the recent rally in fuel cell stocks. Yesterday, Plug Power ( PLUG ), a stock that traded at a mere 15 cents last year, finally fell sharply from its high above $11,70 (yes, it has risen by about 77 times in a few short months) after Citron Research remarked that nothing – absolutely nothing – has actually changed at the company. According to MarketWatch : "Plug Power shares traded at their highest in five years, and the stock was the second most active in U.S. markets in early trading Tuesday. Then Andrew Left of Citron Research came out and said Plug Power PLUG -1.16% shares would be fairly valued at 50 cents. Shares of Plug were recently down 25%. "It's a casino stock, "the lowest form of speculative moonshot," Left said in a note Tuesday.