By David Russell, reporter at OptionMonsterNEW YORK -- Coal miners dominated Wednesday's market gains, and bulls clambered for exposure to Peabody Energy ( BTU). OptionMonster's market scanners detected huge volume in the St. Louis-based company, with more than 36,000 contracts changing hands. That was almost quadruple its daily average. The first big trade that caught our attention entailed the purchase of 2,500 January 25 calls for $1.32 and the sale of an equal number of January 19 puts for $1.92. Owning calls locks in the price where shares can be sold, while selling puts can make money if the stock climbs or holds its ground. Combining the two strategies is strongly bullish, letting the investor collect a credit of 64 cents and carrying the potential of infinite profits if the stock rallies. But he or she also faces losses to the downside. Peabody shares rose 2.1% to $20.90 Wednesday. The stock is up 10% in the last two weeks as improving sentiment toward global growth lifts economically sensitive material stocks. Later in the session, an even larger Peabody trade occurred in the form of a call spread. More than 9,000 June 21 calls were bought, mostly for $1.05, while a similar number of June 23 calls were sold for 35 cents. The trader stands to receive $2 if the stock closes at or above $23 on expiration, a profit of 186%. Calls accounted for more than 80% of Wednesday's total volume in the name, a reflection of the bullish sentiment. Russell has no positions in BTU.