Amazon.com Inc. gapped down under a key psychological upper level at the $3,000 mark on Friday morning and then slid about 3 percent lower before bouncing temporarily and dropping toward the low-of-day again. The tech giant has plummeted almost 10 percent this week and is down more than 21 percent off its all-time high of $3,773.08. Amazon is the third-largest holding in the SPDR S&P 500 ETF Trust, after Apple Inc. and Microsoft Corporation, with a 3.6 percent index weighting and its weakness has been dragging the general markets down with it. The dramatically lower prices are the result of both fear hitting the markets ahead of the Federal Reserve’s monthly meeting next week and the result of negative delta options trading, where the traders began aggressively selling their call positions and buying puts while also selling their underlying shares. Graphic: Spot Gamma’s HIRO suggests selling of calls and buying of …