Shares of Camber Energy Inc. /zigman2/quotes/201242655/composite CEI -4.24% plunged 50.2% in volatile trading Tuesday, as they extended their selloff from a near two-year high. The oil and natural gas company's stock had rocketed 161.6% amid a six-day win streak -- the average daily volume was 523.3 million shares -- to $3.82 on Sept. 30, which was the highest closing price since October 2019. Kudos to Tuttle Capital Management Chief Executive Matthew Tuttle, who said last week that the rally looked like a "headfake," as it appeared to be a possible pump by some Wall Street investors using social-media volume as a tool, as MarketWatch's Thornton McEnery. Since then, the stock has plummeted 59.7%. As of Tuesday afternoon, trading volume was 227.5 million shares, enough to make Camber's stock the most actively traded on major U.S. exchanges. It has been halted three times for volatility in the past half hour. The selloff comes as original meme stocks AMC Entertainment Holdings Inc. /zigman2/quotes/200235402/composite AMC -6.30% rose 2.4% and GameStop Corp. /zigman2/quotes/203755179/composite GME -7.09% gained 0.1%, while the S&P 500 /zigman2/quotes/210599714/realtime SPX -0.42% advanced 1.3%.