Not gamma, but maybe one of the most relevant recent developments: The crash of the japanese Yen.
The BoJ is pumping money into the system to prevent a collapse in the bond market and defend the 0.25 percent ceiling of 10Y JGBs. As a result the Yen is crashing, which is again one of the drivers of the massive dollar rally.
If Japan breaks, many more things will start to break - and possibly very fast with enormous consequences not only for the financial system.