Investors with a lot of money to spend have taken a bearish stance on Mastercard (NYSE:MA). And retail traders should know. We noticed this today when the trades showed up on publicly available options history that we track here at Benzinga. Whether this is an institution or just a wealthy individual, we don’t know. But when something this big happens with MA, it often means somebody knows something is about to happen. Today, Benzinga’s options scanner spotted 23 options trades for Mastercard. This isn’t normal. The overall sentiment of these big-money traders is split between 30% bullish and …