Traders are making huge bets that the Toys R Us bankruptcy will crush one of its main suppliers (MAT)

Toys R Us isn't a public company, but its bankruptcy filing two days ago is already sending shockwaves through the stock market. Feeling the heat is Mattel, the retailer responsible for the wildly popular Barbie and Hot Wheels brands, as well as one of Toys R Us' most important suppliers. The company's stock dropped 6% on Monday amid news that the retailer had sought Chapter 11 bankruptcy protection, hitting its lowest level since 2009. And traders are betting that the pain is just getting start...