GameStop stock’s best day since January driven by fresh wave of speculative bets

Traders are piling into long-shot GameStop Inc. call options that would pay off if the stock price nearly doubles before, or shortly after, the company’s Dec. 6 earnings report, FactSet data show.

Among standardized call options expiring on Dec. 8, two days after the company’s upcoming earnings report, investors have piled into options with strike prices at $20, $22, and $22.50, along with other contracts even further out. For a $22.50 call to be considered “in the money,” the stock would need to climb at least 40%. Shares…