Bullish bettors are buying calls on rare-earths specialist Molycorp, Inc. (NYSE:MCP - 10.01) today. The stock's December 11 call has seen 2,772 contracts cross the tape so far, with 76% of these options trading at the ask price -- indicating they were purchased. What's more, implied volatility on this front-month strike has surged 10.8 percentage points, which is indicative of rising demand. The MCP December 11 call already carries open interest of 7,884 contracts, but it certainly looks as though new long calls are being added at this strike.

Based on the option's volume-weighted average price (VWAP) of $0.17, today's December 11 call buyers need MCP to rise above breakeven at $11.17 by the time the closing bell rings this Friday, Dec. 21 -- when the front-month series is due to expire. From its current perch at $10.01, the stock would need to surge more than 11.6% by the end of the week.

Taking a broader look, optimistic option activity is nothing new for MCP. During the past five sessions, speculators on the International Securities Exchange (ISE) and Chicago Board Options Exchange (CBOE) have bought to open 18,821 calls on the equity, compared to just 11,312 puts. In other words, traders on these two exchanges have favored bullish bets over bearish by a margin of 1.66 to one over the past week.

MCP has been on the upswing since hitting an annual low of $5.75 back on Nov. 16, with the stock guided higher by its 10-day and 20-day moving averages over the past several weeks. This technical rebound could have short sellers on edge, as a staggering 37.6% of the equity's float is sold short. With options players taking a shine to out-of-the-money calls on MCP, it's possible that some of these speculators are actually short sellers looking to hedge against a continued rebound.