Investors with a lot of money to spend have taken a bearish stance on Simon Property Group (NYSE:SPG). 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 SPG, it often means somebody knows something is about to happen. Today, Benzinga’s options scanner spotted 8 options trades for Simon Property Group. This isn’t normal. The overall sentiment of these big-money traders is split bet…