The $TED spread is the difference between the 3 month LIBOR rate and the 3 month T-Bill rate. The TED spread is a proxy for perceived inter-bank credit and liquidity risk. As you can see, in 2008-09 the TED spread ballooned as credit markets locked up and liquidity dried up.
Today, the $TED spread stands at its highest level since 2009. Additionally, the volatility in the spread is increasingly getting jiggy as the steepness of the ascent sharpens. The why’s, what-fors, and how comes are way above my pay grade but I can say for sure it is not a data point that can be ignored.